My suspicion is Thompson will draft BPA on his board or trade to a position where the guy he wants, fits.
There is a parallel situation in history for some guidance.
Following the 2005 season, Thomson cut ties with two starting LBs in the 4-3. Paris Lenon left for Detroit as a free agent. Na'il Diggs was released. These were solid if unspectacular players; both went on to start for 5 or 6 years with other teams.
That left Barnett, Popinga with a couple starts in his 2005 rookie year, and nobody else I can remember.
How did Thompson address these holes a LB?
He drafted Hawk with the #6 pick and another LB, Abdul Hodge, with the #67 pick in the 2006 draft. He also signed a FA LB, 4 year vet Ben Taylor, who'd been a starting LB with Cleveland the year before.
Don't be surprised to see similar moves in the draft, and in free agency as well if Hawk is released. Even in the world according to Ted Thompson, at times need trumps best value.