I think I need to explain a few things, since this constant game of telephone is getting ridiculous.
The GitHub repo was DMCA'd by a representative of Nicalis,
who claimed it contained Cave Story's source code. Whether a decompilation counts as a source code leak is probably up for debate.
What prompted this, we don't know. Some people blame Ewan, claiming he sent CSE2 to Nicalis and that this was what prompted the takedown.
Did he do this? Yes and no:
Did he hate this project and want it taken down, so he wrote a detailed report of what CSE2 is, and sent it straight to Nicalis's legal team? No.
Did he like the project, and DM Tyrone a link to a shitpost CSE2 fork on Discord as a joke? Yes.
Here's the thing: Ewan is far from the first person to tell Nicalis about CSE2. When
heyjoeway's Nintendo Switch port came out, there was plenty of controversy about it in the /r/CaveStory Discord. Among it was the claim that Nicalis had been informed, and that they were "planning an appropriate course of action". This was a whole year ago. In fact, if I remember correctly, Super (who claims to have a contact within Nicalis) was adamant that Nicalis knew about CSE2 since even before then.
Notably, heyjoeway's repo was one of those affected by the DMCA takedown. Meanwhile, CSE2-Minus (
not vanilla CSE2), which was the thing that Ewan sent Tyrone,
was not taken down.
It is not clear at all whether Ewan is the reason CSE2 was taken down, so it would be nice if people stopped treating it as a fact. It's easy to
blame the guy with an awful reputation who made an easy scapegoat
by implicating himself mere minutes after the takedown, but that doesn't make it correct.