It does not imply any of that sort. Nighthold is finished and part of the game client right now, when it opens up is irrelevant of the patch currently deployed on the servers.
Emerald Nightmare is being introduced in 7.0, but do we have it right now? Will we have it come August 30? No? Its opening weeks after the patch happened, and so will Nighthold - weeks after 7.1. They won't be releasing the new mini raid and Nighthold at the same time, even if they are technically in the same "patch" - mostly because Nighthold doesn't actually need any patch, its been developed as part of 7.0 and tested on the Beta already. Its pretty much ready to go, sans some balancing.
Proper content pacing is an important tool for them, and they won't do the BRF mistake again and releasing content too soon, they have specifically said as much.