You guys are all conspiracy theorists.
What actually happened: someone who knew someone at Grindr said "man, anti-zionism is really gaining ground on Grindr, huh?" The Grindr employee said "Huh?" "Oh yeah, its like on every other profile." "Huh...."
Then a few employees chat about it, until someone mentions it to their ad exec, who says "HWAT???" The ad exec knows that the Israeli government is committing war crimes - but they also know that as soon as the right wing media picks up on this, Grindr will become the "the secret deviant app for jew-hating gay nazis", and they DO NOT want to spend their weekend handling that shit storm.
Hence the rule.
You can still say "Pro Palestine" in your bio.