Update #2:
In case you missed it at the raid last night, here's the announcement - we're done raiding until Nighthold! We're going on break a week earlier than planned, because, you know, fuck it!
We've had a solid first tier of raiding for the expansion, and it's time to stretch our legs and cut that shit the fuck out for a while, so when Nighthold is released we'll be ready to go!
If your gear is not where you want it to be (above ilvl 870 is preferred for starting Nighthold), then make sure you keep doing some Mythic+ stuff, world emissary quests, etc.
The week Nighthold is released, we will raid THREE times, on TUESDAY, Thursday, and Sunday, like we did when Emerald Nightmare was released. It worked out very well for us then, hopefully it works out well for us this time. After that first week, we'll be back to two nights a week.
From what I can find on the magical internet, Nighthold looks to be release in late January or early February. In the meantime, get some rest!
Edit:
Don't forget that there's a questline for "unlocking" Nighthold! I don't believe there's an official attunement, but I'm sure there will be benefits to having the questline complete before beginning the raid.