In the menu to customize your appearance, if you choose the option to select the face of an in-game player, there are 33 empty spaces labeled "?" that represent characters that are yet to be added to the game. I'm pretty sure I've figured out exactly who these 33 characters are, with even a rough estimate of who would be in each empty slot in the list of faces. I of course can't guarantee that I'm correct, but I can show the logic I used. (Scroll down to the big text heading if you don't care about that part)
We know this game is essentially a slice of Pawapuro 2022 translated to English, so any characters in 2022 should be eligible to be added. But 2022 has received periodic updates since its release, so which version of 2022 is WBSC Power Pros based on? Well, wikiwiki.jp has a list of every character in the game here:
(Link) and each character's page can tell you what version of the game they were added in. Luckily, no Success or Pawafes characters were added since release, so we only need to look at the shop characters section (パワプロショップ(サクスペ連動))
After looking through every shop character in Pawapuro 2022, the most recently-added players who are also in WBSC Pros are the trio of Pink, Mokoba Moko, and Domon Kion, all added in the v1.03 update. Therefore, anyone from before that update should be eligible. There are 4 shop characters who were added early enough and aren't in WBSC Pros yet:
Mine Kosei (base game)
Suwano Seito (v1.01)
Kyril Foster (v1.02)
Amezaki Yuuki (v1.02)
As for the non-shop characters, we have 3 who appear in Success Mode:
Dadanda Dan, the last of Aoharu High's main cast to not be added.
Hinowa Akira, a rival in the Aoharu storyline in a similar role to Izayoi Mitsuru.
Onowake Torafumi, a member of 2018's Goryo Kaku High, who sometimes appears as an opponent in plot-irrelevant matches (and whose teammates are already in).
And now for the Pawafes characters. Do we have enough Pawafes characters to reach 33? I won't bother to list them all here, but if we don't count Atsumori's base form because he's already in WBSC Pros twice, and we do count Phoebus, who isn't in the shop but is unlocked by default, we have 26 Pawafes characters yet to be added.
For a total of exactly 33.
So without further ado...
List of Characters Coming to WBSC eBaseball Power ProsPawafes Characters
1. Bitou Chihiro (OF/1B/3B)
2. Takeno Kouta (3B/OF)
3. Roddy Bright (P)
4. Nanuq Akiack (C/1B/OF)
5. Takarazuka Getto (SS/2B/3B/OF)
6. Amagi Shun (P)
7. Bu Shuei (1B/C)
8. Kanekura Yohei (3B/OF)
9. Simon Taiji (P)
10. Suzuki Seigo (2B/3B/SS)
11. Akahara Kanpachi (C/1B/OF)
12. Ohgoe Seiryo (SS/2B)
13. Lancelot (P)
14. Kishida Taku (1B/3B)
15. Oda Maito (3B/OF)
16. Namikaze Meika (2B/1B/OF)
17. Saga Iwao (OF)
18. Komasaka Shun (2B/3B/SS)
19. Sumera Mikado (P)
20. Myojin Akira (P)
21. Gundo Hideo (1B/OF)
22. Afro Ikari Mamoru (P)
23. Dark Hoshii Subaru (P)
24. Satoh Taro (1B)
25. Reibu v2.0 (P)
26. Phoebus (P/1B/3B)
Success Characters
27. Dadanda Dan (OF/3B)
28. Hinowa Akira (P)
29. Onowake Torafumi (1B)
Ver. 1.03 and earlier shop characters
30. Mine Kosei (2B/OF)
31. Suwano Seito (C/OF)
32. Kyril Foster (P/C/1B/2B/3B/SS/OF)
33. Amezaki Yuuki (P)
And just to double-check, we can see if everyone's slot in the appearance select screen makes sense:
1. Kodaka > Bitou > Ozora (among her St. Jasmine High teammates)
2. Shogogetsu > Takarazuka > Ogane (at the start of the list of Kurogane High players)
3. Sakamoto > Mine > Tsuruya (among other 2016 shop characters)
4. Moroi > Amagi > Uraga (between his Taiheiraku High teammates)
5. Yashima > Bu > Furunaga (at the start of the list of Bunbu High players)
6. Chouno > Takeno > Victor (I'm guessing here, but he was probably added to the shop in 2018, which is when Victor and Chouno were added)
7. Haizuka > Simon > Naito (between his Vamp High teammates)
8. Naito > Nanuq > Hakata (part of a disorganized series of players added in 2018)
9. Marushima > Kanekura > Shinonome (at the end of the list of Dan & John High players)
10. Maguro > Suzuki > ?
11. Suzuki > Akahara > ? (Two characters slot in after Maguro, their teammate from Shirasu Suisan High)
12. Akahara > Saga > ? (the first in a list of secret characters in 2018 Pawafes)
13. Saga > Afro Ikari > ? (next of the secret characters)
14. Afro Ikari> Dark Subaru > Queen Cocoro (last of the secret characters right before the final boss)
15. Queen Cocoro > Satoh > Narumi (Satoh comes after the final boss because he's technically a manager)
16. Ino > Ohgoe > Shido (between his Meikyo High teammates)
17. Arakata > Komasaka > Aasa (at the end of a list of 2020 shop characters)
18. Aasa > Lancelot > Modo (between his Entaku High teammates)
19. Modo > Kishida > Y. Yumeshiro (end of the list of Entaku High players)
20. Oto > Myojin > Nagase (in a list of characters who were added to the shop or to existing Pawafes teams in 2020)
21. Yamino 1 > Oda > Kirisaki (between his Ebiru High teammates) (Yamino 2 (maskless) is not next to Yamino 1 in 2022, so it's most likely Oda here)
22. Gobu > Gundo > Zento (in a similar spot to his teammates Myojin and Nakanoshima. I dont know why Ebiru High is in the middle of this jumble lol)
23. Tatsui > Roddy > ? (another 2020 addition)
24. Roddy > Namikaze > Tatehashi (separate from her Girls Challengers teammates because most were added as shop characters before her)
25. Black > Sumera > Honba (in a list of characters added in 2022)
26. Morumoto > Suwano > ? (first shop character added to 2022 in an update. Listed here after other shop characters)
27. ? > Phoebus > Alan (down here with the more recent final bosses for whatever reason)
28. Reibu > Reibu v2.0 > Ozaki (right after his base form at the end of the 2022 Pawafes characters)
29. Itto > Onowake > Kujo (between his Goryo Kaku High teammates)
30. Rokkaku > Dadanda > Awate (between his Aoharu High teammates)
31. Awate > Hinowa > Izayoi (right after his Aoharu High rivals, and before their other rival Izayoi)
32. Akechi > Kyril Foster > ? (next to other characters added in v1.02)
33. Kyril Foster > Amezaki > Shirase (next to his Hanamaru High teammate Shirase, who was also added in v1.02)
AND ALSO...There are two alternate forms of characters who have the same appearance as their base forms, so they wouldn't take up slots in the appearance menu even if they are in the game.
34. Ikari Mamoru (Kaiser Rising ver.)
35. Nijitani Makoto (Angel Fall ver.)
So that's 35 probable new additions? Am I wrong? Reply to the thread and tell me why I'm wrong, there's no way I went through all this without being wrong somewhere.