It looks likely that only a few of those rescued by Loki, Korg, and company (from the battle on the Rainbow Bridge) may have survived, probably escaping aboard Grandmaster Goldblum's pleasure craft (or escape pods we never saw) while the rest were killed. But it seems improbable they were the only ones.
First, Asgard ruled... er, maintained peace in a benevolent manner... over Nine Realms. It wouldn't make sense they did it from a single world, especially a large, flat-earth discworld asteroid with its atmosphere. They would have had to have a bunch of outposts and fleets of space-faring warships to supplement the Bifrost.
Mind you, Loki kind of let everything go to hell when he was pretending to be Odin, and when word spreads about what Hela did, and then Thanos (and what perfect timing that was, almost like he arranged it), those outposts and fleets are not going to be able to help Thor and the others because they will be very busy just trying to survive.
Second, it's also possible that not all of the survivors from the Asgard capital tried to escape using the Bifrost. Heimdall may have sent some to escape by other means. Space vessels may have been one way, but Hela would have locked them down after her return. The other way was revealed in Dark World when Heimdall said "There are other ways off Asgard, known only to a few", and we assumed only Loki knew of these. Heimdall and Odin probably did too, but they wouldn't be sharing that knowledge.
These other 'gateways' to other places could have been used by survivors, with the rest being either cut off by Hela's forces or deliberately trying to use the Bifrost to distract her while the rest used the other ways. This allows Thor's ship to get blown up in Infinity War in a manner that leaves no survivors but doesn't undermine New Asgard on Earth where any other survivors from fallen outposts can rally too.