Hard to argue that fan regard for TLJ won’t improve over time. To what extent is obviously up for debate. But a lot* of the complaints from fans have to do with expectations not matched or disliking how preexisting characters were used. As the years go on, and the younger fanbase (who don’t have the baggage of years of expectations) grows up and becomes a larger percentage of the whole, TLJ will certainly improve in standing. The same exact thing happened with the prequels (even as the critical appraisal seemed to go in the opposite direction).
*If you’re thinking of responding to this saying “but not all of the complaints,” how about just don’t respond instead. That’s not what I’m talking about and I’m very tired of that kind of bullshit at this point.
It’s actually pretty easy to argue, that fan regard won’t necessarily improve over time. You more or less regard the very negative opinions as outliers that will in future get less weight in the overall assessment of TLJ, but you totally disregard the positive outliers with extreme praise, that also stem from mostly older fans, who were pleased the ST distanced itself from the PT in both visuals and style. Additionally you disregard the effect episode IX will have on the overall assessment of the trilogy including TLJ. ROTS is largely lumped in with the other prequels, despite the fact that it was actually positively recieved, because the entire trilogy was mostly seen as a disappointment. It is quite possible episode IX will please neither fans or critics of TLJ, and so the entire trilogy may end up being regarded as pretty mediocre, and a missed opportunity. Anything is possible at this point. TLJ may improve in standing, or it may not.