Not that I'm excusing the 1.0 release, I also think it jumped straight to an ending even though there still felt like there could've been more to it, but version numbers are completely made up anyway, they're not strictly, 0.01 - 1.00, increments of 0.01 or whatever, so it jumping from 0.34 to 1.00, doesn't really mean anything, it doesn't mean there should've been 66 more updates or even half that number, really only felt like they were a few updates off finishing up with it, but certainly not a single update though.
Version numbers are more of a way developers give themselves deadlines on when to finish a game, or give potential players the ability to make a very rough estimate of how much content can be expected (Not a reliable estimate though).
0.34 to 1.0 could be 66 more updates, or just 10 more. Depends on how significant the update is, and how much closer said update got the game to what the developer wants to finish it at.
Instead what you see with Shelter, is it got the slasher axe. Its life cruelly cut short by Jason.
I'd add more slasher-film/game references but those are the only two I can think of.
Anyways. You can also roughly interpret how many more updates can be expected dependent on the increments of previous updates, though that, like the other method, is unreliable at best.
(Excluding certain developers whom follow an easy-to-understand version numbering formula.)
Ngl though, I'd be unsurprised if the same thing happens to TFoI.
It's really following the same theme.
Lackluster updates that add little to no content, and then no updates.