No, this won’t kill Reddit. If they can essentially remove every third-party app, they’ll easily be able to start selling user data. Whether we like it or not, the majority stayed on Reddit.
Nothing short of somehow breaking through ad blockers like Twitch did will make people stop using it, even if that.
I 100% refuse to buy a car unless there’s a jailbrake option. I don’t want to get an update while I’m trying to get to work