Call me naive, but I think it's gonna hit 1.0 in a year or so and with modding + console versions I expect to see up to 100k concurrent players on steam in the future. They just have to play their cards right and make sure beta delivers. Survivor Gamez is being worked on. Bigger streamers like Lirik are gonna come back (even today he said that he's looking forward to DayZ's next update as a new starting game)

Twitch and people streaming are big influencers when it comes to popularity of games nowadays. DayZ has a long history there, if it actually turns out great most of the people will check it out again. BR mod is only a matter of time, whether it's something official like SGZ or a simple mod made by community. This will attract a decent number of PUBG/Fortnite players for sure.

The worst case scenerio we're gonna end up with something similar to arma 3, ~20k concurrent players which still isn't that bad. But I can't really see it judging how popular the game is already, and there wasn't any marketing done other than the one early access launch trailer.