I wasn't very socially plugged in at the time so I really have no idea on that last question sadly.
I feel bad spoiling all those things now. X ]
STO is Star Trek Online, an MMO-like game where you do missions and buy starships. Since it's monetized around the ships and players want to collect them, the gameplay is less important to understand than the massive catalogue of ships they've been building up over the years, many of them designed with close attention to Star Trek film and TV design conventions and designers and with a couple of notable designers of their own whose names are known in the community etc. Meanwhile TV-canon Trek came back, but the first couple of years with Discovery and Picard were light on ships and heavy on reuses (especially Picard) and the disparity got big enough that the show teams got together with STO, and Picard S2 and S3 took advantage of this existing catalogue of ship classes and names and sometimes even the game models themselves. Some of the major players like the Stargazer, Titan-A, and Intrepid were invented for Picard, but basically everything else in Starfleet now that wasn't in First Contact came from STO in one form or another. The Odessey-class Enterprise F is a fan favorite design that's been in STO for ages and fanonically treated as the proper successor to the E until Picard made it canon, and backgrounder ships like the Voyager-B and the Reliant class and so on all came straight out of STO.
STO has its own story and histories for the various crew members of the TNG, DS9, and Voyager casts, as well as its own galactic political developments with various hostilities and alignments over time among the various factions. It's even got novels. Less of that actual story material has been integrated into the events of Picard, and even the ships that Picard adopted weren't necessarily brought in with their histories intact. Like timeline-wise, the Enterprise F was decommissioned in Picard before it was launched in STO's timeline.