There are probably very few entities publishing the QID about them in their twitter profiles (of course @vrandecic is one of them) but that could be encouraged, even as workaround for new twitter policy.
It's not necessary of course, Wikidata could be queried for #P4033 and #P2002. Anyone can help by adding #P4033 claims to the Wikidata item about your favorite marginally notable entities.
@kiwix Yes, I have queries here:
https://www.wikidata.org/wiki/User:Nemo_bis/Queries#Famous_people_on_Twitter
But for most of the academics etc. who recently joined Mastodon we don't have a #P2002 statement on #Wikidata.
BEA
ilwoody
mlinksva
Nemo_bis 🌈