I was dumb to not check it myself.

Crypto is no longer listed under Prohibited Industries for paid promo on X.
The ban was there since at least June 2024. Now it's gone.
The policy page changed recently. On February 16th it was still there (Screenshot via Wayback machine).
The entire "financial products" category was removed. Loans, investment services, crypto. All of it.
Gambling was also removed. Weird.
Meanwhile they added pharma, tobacco, weapons, and weight loss to the list.
Crypto paid partnerships are allowed if you follow disclosure rules.
This matters for every KOL running paid promos.
Go check it yourself.