Jinbe's character and relationship with Luffy was built up since Impel Down though, so not really a fair comparison.
I think its a fair comparison because the circumstances are still the exact same in terms of joining. Jinbei was given a full invite, he wanted to join, but had prior commitments like Yamato does now. Jinbei was freed from Impel down, but so was Yamato from her fathers abuse... He also freed Wano which is a pretty big deal for her.
Not to mention that it's a pretty unreasonably high bar, as Jinbei's extended arc is more involved than Ussopp, Chopper, Sanji, Brook and a few other Straw Hats. Even so, Sabaody to Marineford = 100 chapters, and the raid was about 69 chapters alone.
I will again once again point out that people were die hard Jinbei deniers just because he didn't join back in FI despite a full invite, and acceptance (which he also took back). There's no hard rejoin point like Wano I admit, but considering releasing Pluton opens Wano's borders I feel like that would serve the same purpose.
That to me, doesn't sound like she's going to be parked there for the rest of the series. I'm not even a big Yamato fan, I hate Oden with a passion and I find it cringey she LARPs as him all the time. But from a logical point of view, she is fully set up to join when Pluton is freed and join for the last stretch... Like Oden did with Roger.