Also something major Ryce found
We're getting the first 3 alt costumes with Cyclops and Colossus! Carol is probably Warbird but Hulk and Spidey are anyone's guess
Great find! If you plug in the text:
"本作をご購入いただいた方を対象に、X-Menのリーダー・サイクロプスと金属の皮膚を持つミュータント・コロッサスがプレイアブルキャラクターとして8/30(金)に無料で配信されることが決まりました! またキャプテン・マーベル、ハルク、スパイダーマンの別バージョンコスチュームも同時に配信されます。今後、2020年初頭にかけてすべてのプレイアブルキャラクターの別バージョンコスチュームを無料で配信予定です。"
into Google Translate, you get this (I've bolded what I think is a key bit of info):
"It was decided that X-Men's Leader Cyclops and Mutant Colossus with metal skins will be distributed free of charge as playable characters on August 30 (Fri) for those who purchased this film ! Also, different costumes of Captain Marvel, Hulk and Spiderman will be distributed at the same time.
From now on, another version of all playable characters will be distributed free of charge by the beginning of 2020."
Adding to that, there's also this (from the same page, further below) regarding the first DLC pack:
"Now, it has been decided that Moon Knight, Blade, Punisher, and Mobius will be distributed from the "Marvel Knights" series as the first playable characters to be distributed in September 2019.
Another version of the playable character costume is also distributed at the same time. Other contents of the first pack will be released in the future."
So my interpretation is: free costumes i.e., "another version" for all the playable characters will be distributed as the game is updated. If so, this is developer support/GAAS that I can truly appreciate.
Disclaimer: this is from Google Translate.