As much as I respect Phil, I don't agree with this proposal.
I think the AD should already be quietly approaching possible candidates, figuring out what the best options are, getting everything lined up.
Then, at the end of the season, he announces the coaching change all at once. Including naming the new head coach. That way the entire family, including '18 recruits, know what the future looks like at the same time as they find out that a change is being made.
Minimize the uncertainty and concern.
And that approach does NOT include naming an interim. Not even Phil.