I think everyone might be overestimating the appeal of this new use of the Star Wars IP, while underestimating the appeal of a new ride--any new ride--in WDW. Again, the Star Wars Weekends they blocked out CMs were moderately crowded at worst--with far fewer guests in costume. At the same time, a ride based on the best example of a "forgotbuster" still commands 2 hour lines. (Tho I think a big part of that is capacity issues--Slinky Dog, another new ride based on a far more popular IP, maxes out at 75 minutes generally because it's such a people-eater.)
That said, any soft opens will have lines, given the nature of Orlando fandom. And Opening Day will have a line through the park to rival Potter--even if Disney has to call in favors from bloggers and reassign CMs to make that happen. It's all about optics and proving their lightsaber swings lower than Harry's wand. That will feed a media cycle that should keep the park crazy through Marathon Weekend, but I doubt we see lines to get into the land itself again outside Christmas week.
Long-term, tho, I keep going back to a post
@Disneyhead made months ago in the Attendance thread:
Overwhelming is a word thrown around describing everything about a WDW vacation. Too much Pre-planning, too crowded, and too expensive.
Everything we've seen suggests this land does nothing to correct this issue. Crazy crowds, $200 lightsabers, a real possibility a significant percentage of day guests don't get on either new ride. I'm the first to remind people tourists don't follow the parks as closely as we do, but they don't live in a vacuum either. Once conventional wisdom among parents in the northeast and other feeder markets becomes it's not worth visiting DHS unless it's an after-hours event or you booked FP 6 months out, I think you might see lower crowds in 2020 than a lot of the fan community seems to anticipate. (Especially if any sort of election year economic uncertainty is added to the mix.)