I feel like a lot of people’s problems with both TFA and TLJ (not all, mind you, both films are far from flawless) - and even the PT to a degree - stemmed from their expectations for how they should be instead of being open to things going down a unique path.
So know that I’m fully aware that I’m setting myself up for major disappointment two years from now when I say this:
Not at least addressing the Knights of Ren in Episode IX would be a massive mistake.
Hoping and expecting are two different things. I hope the Knights of Ren all wield lightsabers and go down in a blaze of glory. I expect them to be, you know, just sorta there in one or two scenes, not really doing much, let alone having their background explained. And if they do get action scenes, they’ll have non-lightsaber weapons.