Hellebuyck is far and away the #1 reason why the Jets are in any sort of playoff conversation.
Maurice deserves credit for coaching a style reflective of the talent of the team - mostly spurred by injury. The supposed top line of ##-55-26 has been anything but going back into last year and the Wheeler-as-Centre-Experiment is mostly working because a) Ehlers is still underrated, b) Roslovic is just better as a winger and probably doesn't have a future as centre anymore, and c) Wheeler loves Maurice, is easily coachable, and does everything the coaching staff wants him to do as a "centre" (which is stay high in the offensive zone and only get low for rush chances and/or outnumbering in a puck battle along the boards. (This is all good because he was cheating a lot for offense as a winger this season so it might be a good reset for him if/when he moves back to the wing.)
Right now we have a 2A and 2B, and even then I think you can flip Connor and Perreault and get a 2C line while improving the gaps of 81, 55, and 29 - mostly for defensive reasons. Before Bryan Little's injury, Maurice's deployment was very much in favour of Scheifele and Lowry's line handling the big defensive responsibilities. Now,
it's a little more balanced amongst the top three, though the 4th line is still largely forgotten. I'm sure it's a relief for Wheeler,
whose defensive impact is a far cry from his 2014-17 seasons, that he isn't overworked and overplayed whenever the Jets are trailing or need to protect a lead. Appleton's return from injury should prove a boost to the 4th line and the waiver acquisition of Nick Shore allows for Gustafsson to get some needed top minutes at the WJC and SHL (though Logan Shaw needs to be catapulted to the AHL whenever feasible).
The defense is an enigma that ebbs and flows from "tolerable" to "jesus christ" and they're really being helped out by that F3 that's staying high in offensive zone to limit rush chances against - there's only 9 goalies with more than 300 minutes this season that's facing less than 1 rush chance per game and 37 is 5th among them (according to Natural Stat Trick). Of course, the big problem right now is that they've been giving up a crap-ton of rebound chances against, and that's where Hellebuyck is shining at the moment (and why the Jets xGA has been sky high this season). They'd be a lot better not necessarily by getting "bigger" and "meaner" in front of the net but by inserting some players that are good at moving the puck out of the zone (hello, Niku). For now, they're surviving - and that's about all you can ask for at the moment. Reinforcements are coming next season (Samberg, Heinola, full-time Niku, Chisholm... maybe even Stanley?).
That all being said, Jets are very much in a bubble that seems bound to burst at any moment. Does it mean we'll flip from going 10-2-1 in November (or whatever it) was to 1-2-10? Probably not - it's more likely they'll be hovering around the middle with lots of close or overtime games, and even though the team hasn't gone to OT lately, their top talent is still some of the very best in the NHL so it's no surprise the team is 6-1 in OT and they continue racking up that 2nd point through those means. They aren't going to be a traditional analytics darling by any means, but their style and how they want to play is pretty evident and in theory should continue outperforming some abysmal publicly available numbers (until it all collapses so don't @ or quote me when Hellebuyck gets injured and everything gets "exposed"). All you can ask for from this team is to play that style and remain in the game to allow their offensive talent to take over, and though I don't necessarily agree that's the best way to coach or win games or win Stanley Cups, it's allowed them to remain in the hunt.
EDIT: Oh yeah, and not taking penalties. Huge swing in the Jets favour as that PK was awful early on and still looks worrisome IMO.