Death warrant? Maybe, but I expect companies (maybe not the EU, but - let's be frank - probably the EU too) to go back into X as soon as they feel they are done cashing in this virtue signaling.
There were plenty of reasons to leave twitter before this idiotic tweet from Musk (reasons due to twitter's action as a company, and not just Musk's drunken posts) and they were all happily tweeting and advertising.
Is this drop that breaks the camel's back? Maybe, but I wouldn't be holding my breath.