This is utter hogwash. Never happened.
I'm very disappointed that Pedes here don't do enough research before posting crapoola such as this. Don't mean to offend you @Deadnought61... just being honest.

A single website mentions this, under the satire section: https://spacexmania.com/hes-too-much-woke-sylvester-stallone-drops-out-of-1-billion-project-with-creepy-robert-de-niro1466/

There would be mentions around the web about this from credible sources.

Mention here, not true: https://uk.movies.yahoo.com/news/fact-check-sylvester-stallone-rejects-180100165.html?guccounter=1&guce_referrer=aHR0cHM6Ly93d3cuZ29vZ2xlLmNvbS8&guce_referrer_sig=AQAAANtw3NVAn6EwhdvcqdAf_JnBNAAP_bO26LqFB2jV9RaDzfniJEvJaZYcADvJ9p5gdMQXtZKt5s9EBxKi-jMiQhf96a8FpugEWCBR1I-JijKLBm9Lc48xsvgK-jX4Q1oE0kUzNWywnzjbVQ-xI8lRV91WUBd2nc_UyIvCjlLaLoOQ

There's also a version of this where Stallone rejects a 100M Bud Light endorsement over the whole Mulvaney woke thing.

(Snopes is a leftist website, but they do often have valid information... ok?) https://www.snopes.com/fact-check/stallone-refused-work-deniro-woke/

Anyhow, please try to research stuff before posting as factual. This doesn't pass muster at all. This is one of SO MANY of these things I've seen posted here, and too many just trust whatever is posted here and upvoted, or tagged by the mods.