From what I've seen of the raid... There's good news and bad news.
Good news is, it seems EXACTLY what an end game division activity should be. This is the true gear test. In Destiny, there isn't really much in terms of builds. You choose a class, elemental sub class, and elemental subclass tree and beyond that only certain exotics will really change up your abilities. Because of that, the raids are designed NOT to require a team composition of certain classes. They do have DPS checks but as long as you have a decent weapon set up (not hard to get) and are a high enough light level (not hard to do) the only thing stopping you from beating the raid is just knowing and executing mechanics.
The Division Raid demands you to know and execute on mechanics as well. I'd argue theirs are slightly less complex than some of the Destiny ones but still require a lot of coordination. The difference is, The Division is more like a true RPG than an action shooter. Your builds are actually important. Every stat is important. From what I've seen of this raid you can be Gear Score 500, be a good player, know the mechanics, but if your gear isn't optimized you are in a lot of trouble. And that is good. Division is a game build around builds and stats and build diversity.
But... The bad news is that its even more hardcore and tough to get into. I was excited to try the raid today at GS 497. But after reading about it and watching streams I realized I'd have to grind some more of the other activities to get better rolled loot to even have a chance. And I largely haven't played in a month. I was thinking about trying to knock out some missions but honestly didn't feel like running old content so I went to play sea of thieves and some rocket leafgue.
I think if they released the raid near the original time table of April 26th or earlier it might have been better. Because World Tier 5 was still more or less fresh, the game didn't stagnate yet, and people would have been cool with trying to gear up for the raid while the hardcore hardcore would have been starting it.
I might try to get some more gear this weekend, since I do wanna tackle it at some point. Ideally, after more people complete it a sort of meta strat will develop and it will become easier.