https://bugs.winehq.org/show_bug.cgi?id=54071
--- Comment #12 from Gabriel Ivăncescu gabrielopcode@gmail.com --- It likely works by luck because it uses the other thread for some non-essential, but it's still a bug and should be tracked along with 37906.
Don't get me wrong, this doesn't mean the patch isn't fine, as a temporary workaround (like stubs are). But it doesn't fix the actual bug so we can't mark this one fixed by using a stub or workaround.
We'll have to wait for Jacek's opinion about your patch though.