Actually, a lot of territorial claims start with "renaming", to provide support for some kind of base for the claim.

That specific case would have been quite minor (in the Trumpian show) except that it comes at the same time as USA (... sorry for all non-Trump supporter, but now that he's your POTUS, he represents all of you) suggest to invade (euh... "take back" ?) Panama and Groenland !

Right now, from outside of the USA, the USA is starting to be seen more as a wannabe-invader than an trusted ally...

So the renaming... that could have been just another Trump-ery (french play on word ;-) )... is taken quite seriously