I think that the idea is workable, but it would need some more wildlife, and maybe the ability to fish in game so that you would just have effectively no bears and fewer boars or what have you. You wouldn’t want to make it any harder than it already is to come into a server that was wiped more than 2 days ago, and by eliminating so much game it would almost certainly do so. If they make food spoil and diversify types of foodstuffs, perhaps going so far as adding salt to cure meats… You might be able to work around the coming winter with relative ease, but it would certainly make it tougher to get started for a new player coming upon the server in Winter.
Rust is the kind of a game that had fairly high attrition of its playerbase on various servers, I’ve personally seen quite a few people who did something silly like not put a ceiling on their base, and then (while they likely won’t ever forget that lesson) decided to give the game a go on an entirely new server rather than build back up. Of course, that’s far more likely for a player making a go of it alone, but even still this high turnover means for a healthy server population you want new people coming in, claiming degrading bases and such.
As the threat of data degradation and corruption lessens fewer servers will wipe on a weekly basis, as patches become perhaps less frequent and contain more content than bug fixes (which is not something that is assured so much as it is somewhat standard with an iterative design process) you don’t really want to discourage a player from picking up on a random server and giving a go of the game, and I can’t imagine that loading into a server and seeing it was winter if it had so many negative effects would encourage someone new to that server to stick around.
Still, seasons could bring something interesting to the game once there was a healthier amount of NPC variety, bears could go away and wolves could hunt in packs and become more vicious and likely to pose a threat to the unwary. Deer could be fewer in number, ideally you’d want the wolf packs to roam and fell deer they came across. Once these sorts of interactions were available, I think it might be an interesting direction to go in, even if it was primarily an aesthetic difference (other than the different NPC behaviors).