I have no idea who, exactly, but it would be probably be seen as a slap in the face to the scouting organization for it to lose it's head and then go outside the organization to replace him. So unless Snead wants a rebuild of the scouting department, it will be an internal promotion.
Snead has done a good job in his hires (as has Kroenke) just as McVay has. There's some real continuity going on here. And this ought to be seen by fans that the NFL sees the Rams as a model organization to imitate. Some people are just good at finding the special guys. And don't think that the FO hasn't known for awhile that it was coming sooner or later that they'd lose Holmes. So they are prepared.