This is hard topic to discuss knowing those companies don't have token yet because there's legal concern.
There's not even guarantee that they will create token at some point, metamask was rumoured to have token but since it's based on the US i don't have high expectation since I'm sure they are trying to avoid their token being considered as security by SEC.
The GENIUS act itself also forbid yield distribution by the stablecoin issuer. Basically I'm still not sure if this is alpha for future airdrop.
But payment gateways are allowed to issue utility tokens. If it really came down to it, they could just spin off their stablecoin operations into a separate business to avoid legal issues.
As for the uncertainty of a future token launch... back in the day, nobody expected L2 protocols to release their own tokens. Even exchange tokens weren't an obvious move at first. But sooner or later, almost every startup in this space ends up launching its own crypto