It is true.
Whereas in every other expansion you could not reach normal mode gear before the raid opens, now you can.
The itemization of the raid items is pretty awkward, the best trinkets and gear do drop in mythic+ dungeons, getting a proc from 865 to 880 is by no means an issue and that is mythic standard gear level. But instead of having 1 weekly reset for mythic+ you can run them all over as long as you have keystones. (which is no problem for people like me who got several alts 840+ extra for keystones)
So even AFTER raid release we will run into this situation.
Tomorrow we as a guild will run into normal mode EN with 25+ players with ilvl 848+, many even 850, few with legendaries even 850+.
I expect to clear it in about 2-3h.
Heroic wont be any problem too, so there goes that.
Its not even worth doing splitraids, at least thats how I feel because the better gear is waiting in dungeons. (and btw mythic+10 is a guaranteed 880+ in a box per week, too)
so we are planning on clearing nhc/hc and then spamming the living hell out of dungeons.
Lets look back at HM progress in WoD:
We got into the Raid with ~20 players with ilvl between 840 to 850 depending on how lucky you were with WF drops, and how many gold you spent on random epics. But only a few hardcore rich people got to ilvl 655 before HM, and even then, the gear was not even optimized properly, because you were limited to world drops (665 items).
so we did need a lot of items in HM nhc.
There is definitely a difference. People are reaching softcaps preraid due to crafted gear, people have with a "normal" amount of dedication at least 845+ preraid.
The difference is too small, the gear we get too good.
And dont you forget the legendaries!
I agree with the op on this.