Aw beeeeeeeeaaaaaaaaaaans I thought this was a late bug in the iOS 11 betas I was running but nope. Looks like this is intended behavior.
Which to some extent I kinda get? Ya feel? But also it's different from how the interface has always worked, and provides no meaningful suggestion to the user that there's been a change.
More importantly... Maybe I'm an odd duck, but I can't think of many situations where I want to disconnect from Bluetooth or Wifi and don't want to make that stick? In the instance I want to drop a wifi network, it's either because I don't want to use wifi (and so would turn it off altogether) or because I want to switch to a new wifi network (and so would use the actual wifi switcher.) Same for Bluetooth. So it seems like these are just kind of... wasted buttons now?