I really wish we had this too. Mainly because I want to go through post-Shadowbringers and the Eden quests in NG+ concurrently - since their timelines mesh together in a pretty important way. It would help if the raid NG+ were broken up into their individual patch parts, instead of just one long story.

It really irked me during ShB NG+ that I couldn't pause to go do one of the role quests in NG+ as well. Since they're linked with the ShB story it doesn't make sense that you can't do them at the same time.