I don't know if this was an intentional change, but I haven't seen anything about it.
The entire time we've been on Vanilla, if I hit Back, I'm taken back to the previous page I was on, but forum content would update (read counts would update, threads would re-order based on most-recent post, etc) somehow.
As of this morning though, I'm not seeing that anymore. If I navigate back, I get the page as it was when I viewed it before, then refreshing will get me the new state.
Is this a bug?
Apple is a terrible company.