https://www.gamespot.com/articles/destiny-2-hits-12-million-players-online/1100-6453235/

Destiny 2 had a strong start, it seems. Developer Bungie reported on Twitter that the shooter had more than 1.2 million concurrent users on September 10. Presumably that figure covers the combined playerbases on PlayStation 4 and Xbox One.

More than 1 million concurrent users is a massive figure. Destiny 2's servers have experienced some issues, presumably due to the influx of users, but generally the game has been stable. To help keep the servers from melting (not literally), Bungie introduced server queues, so some players in particular regions may have had to wait to log in.