Apparently using a URL shortener will bypass this

X (formerly Twitter)

Insider Paper (@TheInsiderPaper) on X

JUST IN: Twitter restricts likes, replies, and retweets if a tweet has Substack links - reports

looks real https://twitter.com/lulumeservey/status/1644332030153445384?s=46&t=8OdgH3WtCG_AKi0ko_4ZGg

Seems unclear if it just an error, spectualtion about competition from 'substack notes' or twitter having substack-like function. Who knows. But yeah I tried it on a post with a (new) substack link and it doesn't register the like.