So I mean, what's stopping us from making it Medievalism Studies?

I mean, hell, even Greenblatt's beloved Poggio was just looking for something earlier to cosplay.
The fact that the humanists grabbed earlier medieval sources for art and script wasn't an oopsie. It was "earlier than Arthur."

If you have a young Edward III literally setting up a joust where everyone dresses as Arthurian characters in order to kick off what he hopes will be a genuine real-life chivalric order of the Round Table (we got the Garter instead. best laid plans, etc) you have cosplay.

And it keeps going. They're editing Chaucer and Langland, etc by the 16thc, and continuously if you consider scribal interventions. And they keep editing Chaucer.

The legal side invents a Middle Ages almost continuously, and pretty self-consciously, as they go, and it gets reinvented and enshrined in colonial law by the 18th (but the theorization begins as early as the 16th).