Yeah the screens will not get removed from Klefki's side if it uses Magic Bounce on a Defog.
Anyway, spinning (and Defogging) got a whole lot easier now that Sableye is gone. Spikestacking teams definitely took a hit, and Froslass offense can't really be used as effectively because of the ease of hazard clearing. Some spinblockers like Doublade, Chandelure, and Spiritomb simply don't have the longevity/bulk to spinblock like Sableye did, and others like Jellicent, Trevenant, and Cofagrigus don't fit on these teams at all.
I want to echo the fact that Klefki is so insanely good at its job and I would really like to see it go. The number of options it has to support itself and its teammates is pretty staggering (they've all been listed in this thread by other people so I won't bother to list them again). In particular, Prankster Thunder Wave is pretty aids and like koko said it just promotes careless playing. Also in particular, it's ridiculously easy to pair with Mega Swampert, which easily switches in on and Mega Evolves against the things that Klefki tends to draw in (Fires, Electrics, bulky Grounds). Klefki, in return, supports Swampert heavily with Prankster Damp Rock Rain Dance, Spikes, and in some cases para support. A Mega Swampert with 6-7 turns of rain can easily be gg against opposing offensive teams. All in all, Klefki is just a little bit too effective at its job given its typing, movepool, and the amount of support it has the ability to offer.
Volcarona is still incredibly broken. It's too easy to set up a Quiver Dance (or more tha none), and once it has, it may very well be gg right there for certain teams. Staraptor is a little bit more manageable thanks to a generally faster tier as well as new checks like (Mega-)Diancie and Bronzong. Togekiss is also pretty broken; while it's slightly more manageable on its own (again, Diancie and Bronzong are some cool new checks) the ability to Baton Pass boosts to something like Mega Sceptile, Pidgeot, or even like Agility Altaria is pretty stupid. All in all, not much has changed for Togekiss so I think overall it should go back to BL.
This is a metagame being dominated by Fairies now with the additions of Mega Altaria, Mega Diancie, Togekiss , Klefki, Whimsicott and even CM Florges. The trends I've seen on the ladder definitely reflect that. Most notably, Scarf Hydreigon has taken an enormous decline as it's now set up on by some of the biggest threats in the tier. Also, Whimsicott is pretty much now delegated to a support role because its offensive Infiltrator set is arguably outclassed by Mega Altaria's special set. Healing Wish is a fantastic option for offensive teams to have with all the setup sweepers available. These are just a couple small trends I've noticed.