You would be wrong... it was perfectly Constitutional, and Lincoln had no part in it. Read some West Virginia history.
When it was obvious that the secessionists would carry the day in Richmond, nearly all members from the Western counties of Virginia, and a few from the eastern, walked out of the legislature refusing to participate and formed their own rump legislature in Alexandria. That legislature was recognized by Congress and Representatives were given seats in Congress. The Alexandria legislature gave it's approval to forming a new state since regardless of the outcome of the war, the vast majority of people in the western counties wanted to be away from the tidewater aristocrats who dominated Richmond and had always treated the west as second-class citizens. Congress accepted the petition for statehood in 1863.
It followed the Constitutional requirements to the letter.
Which is the fatal weakness in your exculpation of Lincoln and the rump faction of Virginians who didn't accept the actions of the other 3/4's of the People of Virginia.
The People of Virginia had the right to reform their government whenever they pleased -- and to secede from the Union, for that matter. Nine guys in a phone booth in Alexandria had no right to call themselves "the People of Virginia", nor any right to attempt to form a government, when the intact government of the People of Virginia was fully functional in Richmond.
States have rights and powers. Dissident politicians don't have the same rights and powers, nor any right to pretend to dispose of same.