I don’t buy the “protest” argument at all (seems a little tin foil hat to me). If hardcore fans didn’t like TLJ, they probably know that Solo has nothing to do with it. IX’s performance will be a better indicator of the true response to VIII. I think the “boycott Soylo” group is a pretty minor demo, especially considering most of those people probably saw it anyway.
It’s all speculation, and I agree that IX’s numbers will be a better indicator. I think they’ll be worse than TLJ’s unless there are some clear indicators from Disney that they’re changing direction.
As always with SW, the fact of the matter is most of the audience is made up of casual fans at best. For them I think the main reason is that they still see Star Wars as one single franchise, whereas something like Marvel is a combination of different franchises (which is to say nothing of the fact that Solo’s performance is roughly on par with most Marvel origin movies). I do think the five month gap probably hurt it, as people aren’t used to so much SW at once, and checked out when they felt this one was skippable.
Unless TLJ is what told them it was skippable, because Star Wars itself has become skippable.