If Dragon actually abruptly arrives at Elbaf to save Luffy, it would be pretty lame tbh. I guess it's better to get it out of the way eventually though
I'd be fine with it for these reasons:
1. Dragon said the real war would start when the God's Knights deployed. I saw this as direct foreshadowing the Revs would fight the God's Knights. Well, here we... might be?
2. Luffy was saved by Dragon during a sudden downpour. Zaza just showed up. Dragon has been historically tied to storms (and I still believe he's the reason Shiki's fleet sunk against Roger in Edd War)
3. BRO DRAGON DO SOMETHING GOD SHOW UP I ACTUALLY FORGOT THIS GUY WAS A CHARACTER FOR A MONTH AND ALL I THINK ABOUT IS ONE PIECE AND OCCULT HISTORY AND MAGICAL ANIME WOMAN, GOD, HE'S THE MAIN CHARACTER'S FATHER, DO SOMETHING, DRAGON, GAHHHHHHHHHHHHHHHHHHHHH
4. After the Vegapunk fiasco Dragon most likely wants to recruit Vegapunk, and will know they're in Elbaph. If the Chimerapunks told Weatheria where they were, I have no idea why they wouldn't contact Dragon. He should know Lilith is in Elbaph.
5. Like with Lilith, Dragon will want to... well, see his kid, Luffy. It's been a LONG TIME and there's a reason this man looks to the east.
6. It's incredibly clear that Kuma and Bonney sailed to Elbaph with the Straw Hats, and the Revs will want to reunite with Kuma as well as protect his and Ginny's daughter
7. Sabo will want to tell Luffy about the nature of the World Government (too late for that, tho)
There's a shit ton of reasons for Dragon and the Revs to come to Elbaph, it wouldn't be a narrative fake-out, IMO.
It's just like borderline impossible to imagine the dude actually... FIGHTING at this point. Like it breaks my brain imagining Dragon actually getting feats in this manga.