The last few Square releases weren't Epic exclusive, if they even released there. However, Square also seemingly changes their mind about this stuff, like people change their underwear, so who knows in the end.
Any studio that looks at sales on Epic vs sales on Steam very quickly learns to not make the same mistake, unless they're not confident on their game and expect it to sell bad.
The only hope I have is that Yoship is doing everything in his power to keep that from happening. Otherwise I'd absolutely expect it to be one after what 7R went through