This is a very good point, it's the same with me after TFA released it kind of reignited my nostalgia quite a lot for all things Star Wars again, i'd say it definitely contributed in me wanting to acquire more vintage toys, and if TLJ was as good as TFA ( story wise ) then I do think SW hype for a lot of people would have carried on going upwards. Unfortunately TLJ had amazing potential to be something special carrying on from TFA but instead was an utter wasted opportunity and has completely killed my passion for the Star Wars canon from this point onward, I just don't give a **** about Episode 9 now, i'm not even thinking about it or waiting for it like I was for Episodes 7 & 8, I don't even care about hearing Ep 9 spoilers, someone could post up right now the ending to the film and i'll just read it lol I don't care where it's going or how it ends. Don't get me wrong I love TLJ as a standalone film I do think it's very good as a sc-fi film that feels like SW, but it's just completely wrecked the whole story which did not carry on well at all from TFA, TLJ felt like it's own separate one off film and not part of this trilogy.
And I know there's a ton of others out there who feel the same, the momentum is gone, so I can see this definitely having an effect on the general populations love for SW with a clear knock-on effect on the vintage toy market. Even the modern toys are apparently doing awful, you only have to search on youtube to see endless videos about stores not being able to even give away figures at stupid prices, a lot of people just don't care anymore. Also Solo should have done a lot better than it did, it's a very good film IMO but I really do think a large chunk of fans are kind of giving up on it all since TLJ disappointment.
It will be interesting to see how things go with the vintage & modern toy market and general SW hype after Episode 9 is released, they'd have to give us something amazing and somehow turn the trilogy around for it to have a positive effect but tbh I think the damage is done now.