You actually have that option now. I don't the specifics (how you do it) but I believe you can choose from two tracks: the traditional "update to iOS15" and "st

You actually have that option now. I don't the specifics (how you do it) but I believe you can choose from two tracks: the traditional "update to iOS15" and "stay on 14 but get security updates". It's new this year though, so who knows how it will work in practice