UESPA existed from at least 2067 until at minimum 2267. 200 years. It would appear the United Earth Starfleet was an offshoot of UESPA circa 2132 and UESPA remained the Earth-based operating authority for Starfleet until at least 2267 or the first season of TOS. After "Tomorrow Is Yesterday" the agency is never again mentioned as existing in the chronology.
Two earth probes (Nomad, and V'Ger) came back from deep space to destroy the federation.
Starfleet distancing itself from honouring Earth Probes by this point seems wise, although if you're going to name a ship "Voyager" after all those people died, they might as well have a "USS John Wayne Gacey" in the fleet too.