There are versions of Kiritsugu that sure would have been in favor of that. We saw how far he went to stop things going down a tragic route for Irisviel and Illya/Kuro. But Miyuverse Kiritsugu for sure wasn't thinking about helping Miyu. Just the best way to sacrifice her. Maybe dying created a sense of regret/clarity, but even then he would still be lying to Shirou there to make himself look good.
Maybe they are really running with the idea that Shirou used the card so much that regardless of it passing to Kuro there was still plenty of Emiya left with him. It was his power he's been using since he sent the card with Miyu. But maybe Emiya couldn't fully be summoned until what remained with Shirou was fully released.
Honestly that also feels like an interesting route for speculation. Presuming Kuro can be brought back then she might come back even stronger with the full weight of the Emiya card supporting her. But I suppose that would only matter depending on where things go from here.
Either way I'm willing to go along with the choice to have Emiya show up when and where he did. Especially if we roll with the re-written history idea. Maybe in that history Miyu came back and passed the Archer card back to her brother at some point. Certainly it harms nothing for an Archer to be a bit far from his target
. Fitting to have things work out like this anyways. All the servants played their parts. But I like the finishing moves to go to Hassan (his card took down Sakura and kicked off Shirou's battle for his sister), Emiya (who of course was very much tied to that journey), and Miyu herself.
Really does leave just dealing with Pandora's Box, Illya/Kuro, and the future of that world.