My gripe regarding excessive allusion is that it threatens to cheapen the value of the original and might, in the end, undermine the experience of the new.
I have the same concern with the Clone Wars, which has, at some point, recycled just about the entire script of all six movies. Actually, someone should make a video recreating the films by splicing together quotes from the Clone Wars...
This is an issue for kids' franchises mainly because the allusion is most likely to be the first time the primary audience encounters the reference. That audience won't catch the allusion until they see the source material. This means that the source material, on first watching, might paradoxically feel more derivative than the alluding media. But once the viewer realizes that the witty quip in the allusion was lifted from the source, it might spoil what had seemed like wit.
I'm certainly not saying allusions should never be made. Alluding to sources outside of the franchise can make the franchise richer, and the "easter egg" effect does have value for adult audiences.
But there does come a point when internal allusions start seeming cheap, like the writers are just cut-and-pasting scripts together.
I'd also like to distinguish between this kind of allusion and an in-joke or a callback. The problem with this kind of allusion is that it always comes off as being the first time the quote or scene is being used in this particular iteration of the franchise. That's different from a callback allusion to previous events or phrases within the current series.
Just my two-cents.