It might run counter to popular opinion, but I think the animated finale was actually a better fit than the animatronics.
Modern WDW seems to suffer from a sort of "mixed media" syndrome, where they're willing to sacrifice consistency for the sake of updating a single scene or two using technology or media that runs counter to the rest of the experience. A microcosm I suppose of their lack of regard for thematic consistency in the parks themselves.
Gran Fiesta Tour is mostly a screen-based experience, save a few basic-motion figures in the "small world" scene. Placing full (albeit historic) animatronics in the finale is jarring because it's a sudden switch from one media (screens) to another.
Another example, in the exact opposite direction, is replacing the animatronic hitchhiking ghosts in the HM-- a mostly animatronic, fully-realized environment-- with screen-based technology. In that instance, the animatronics worked better because they were consistent with the thematic foundation firmly established throughout the rest of the ride. The use of flat-screen hitchhiking ghosts comes off as a tacky afterthought, not only because it is dimly projected and horribly executed, but mainly because the rest of the ride is layered with fully-realized sets, three-dimensional characters (even Leota and the singing busts, while they do use projection, are three-dimensional figures), and painstakingly crafted detail.
I appreciate WDW resurrecting the old Mickey Mouse Review animatronics for Gran Fiesta Tour. But the screen-based finale had humor and nuance (especially Donald's performance) that the audience expects (based on the rest of the ride) and which the animatronics are incapable of portraying.
A better idea? Wait until *after* the finale to introduce the AAs. Place them around the corner, in the intimate, but sparse and under-utilized section of the ride just before unload. Give them snappy dialogue (or just sync them to the dialog that already exists in that section). What you end up with is the classic Disney unexpected "plus"-- at the very end of the ride-- which works thematically (because it's more of a post-show than a part of the main attraction) while preserving the consistency of the experience.