I think that the brands aren't going to slow it down anytime soon.
Why? Because their job is to sell watches, it's simple as that. Thay don't care if passionate collectors cannot buy at retail as long as the demand is so high that they don't even need to fill the trays in the shops. There are simply too many people with too much money looking only to gain followers on social media and this is just doing the brands a favor.
When an OP is listed at 35K, a Nautilus gets sold for well over 100K (or maybe 200k, I don't know), a RO goes for more of less the same amount of money it's clear that something is wrong. And it's not the Grey's fault IMHO. Their job is too sell watches too and if people buy at their asking price it only means that these resellers are right. Supply and demand they call it.
So when will things change? Well, in my humble opinion we just have to wait for the next big thing, whatever it will be. At that point watches will start losing their Instagram appeal, the Greys will find themselves sitting on a pile of overpaid metal and they will have to lower their prices just to pay their bills. Magically the boutique trays will start to fill again and the real aficionados will be able to buy the pieces they want at retail or even with a discount.
When will this happen? I don't know, no crystal balls here sorry. My impression is that it's only a matter of time.
There's one thing that I'm 100% certain of: I will never ever buy ANYTHING over retail. Never. Not only that: I will never ask to put my name in a waiting list for anything. Nothing deserves this IMHO.
But hey, maybe it's just me. I know that there are many real passionate collectors that would happily wait years for an application only piece, I respect that. It's just not my thing.