Yeah it's a good choice of words. Users can also check whether the relays they are connecting to claim to support NIP-09 (e.g. load the relay in snort to see what NIPs are supported). If you only connect to relays that advertise support for NIP-09, I think there's a decent chance your request will be honored.
Discussion
Sounds right. The only circumstance where it may still exist is if someone had re-broadcast your post to their connected nodes and one or more didn’t support the NIP. Probably a rare occurrence but still something to keep in mind.