While I understand where you're coming from, it seems plausible (though, most likely a bad idea, as it seems likely there would be incongruent data) that if you had all prodinfo/keys/etc. from the "unhacked" Switch on your emuNAND (aka, essentially you ran the NAND of the unhacked Switch on the hacked Switch), that, to Nintendo, it'd look like the unhacked/unbanned Switch was the one trying to authenticate.
Of course, you *do* run into another problem where, during authentication, information is fed into the Switch hardware (decryption, keys, whatever else), and since you're running the wrong NAND (via emuNAND), it'd get bad results. Even if you successfully connected to Nintendo's server, and successfully joined a game, and played a match, your unhacked Switch would most likely be flagged for the next ban wave (because of mismatched keys, or something similar).
So, I suppose that if you spoofed enough data, maybe it'd work, but more likely you'd just be setting up your "clean" Switch for a ban.
Of course, what do I know. There's many very smart people already working on unbanning Switches. Since I haven't seen anyone mention anything (regarding using emuNAND to bypass a ban), it's almost certainly not that simple, and not possible at this time.