In fact the term doesn't end until tomorrow.
But more importantly, the next semester and thus the official start of him being a student at the U doesn't start until Jan 16.
And he is not a student at the U, yet.
New Hampshire semester ended yesterday. He is no longer a New Hampshire student.
He is starting Gopher practice on Friday. Gopher semester is over then, too.
Either way, it isn't a "mid-semester" transfer.
And, yes, this rule has been in place for years. In fact, college hockey has used it often. Kid transfers after first semester and starts practicing with the new team well before the new semester starts.
It might be a good idea for you to sometimes acknowledge you don't know everything. It is okay to admit you were barking up a wrong tree and move on. You don't have to dig in on everything and clog the board with idiocy.