Germany does not have something called "fair use," but it does have provisions for uses that are fair. For example your use of the three words to talk about their copyrighted status is perfectly legal in Germany. That somebody wasn't allowed to use them in a specific way in the past doesn't mean that nobody is allowed to use them in any way.
To be pedantic, short quotes (as opposed to short copied fragments that are not used as quotes) are explicitly one of the allowed uses (Zitierbefugnis). You can even quote entire works "in an independent scientific work for the purpose of explaining its content"! https://www.gesetze-im-internet.de/englisch_urhg/englisch_ur...
Generally speaking, exceptions to copyright are based on the appropriateness of the amount of copied content for the given allowed use, so the shorter it is, the more likely it is for copying to be permitted. European copyright law isn't much different from fair use in that respect.
Where it does differ is that the allowed uses are more explicitly enumerated. So Meta would have to argue e.g. based on the exception for scientific works specifically, rather than more general principles.
Of course, but „it’s a short quote so you can use it“ is not true (at least in Germany).