I would think that the team has likely checked with the NFL to see if Hill would still count as a QB if they changed his designation to TE. There is certainly ambiguity in the phrase "is an established quarterback." They give examples of what could make someone an established QB, but that too isn't really clear since it could mean a guy who played QB in college but never did in the NFL which doesn't seem like it should count. I mean what if a guy was only a QB as a redshirt freshman?
But, one way or another we will find out if they will/can use the emergency QB designation about 90 minutes before kickoff. Underhill has been talking like they can do it and will do it.