Yes please keep him.
Deal out Boeser, (and if possible-Poolman, Dickinson, Halak) at the deadline.
Use the remainder of the season to integrate the acquired assets into our roster/system.
Bring up Rathbone for some late season experience/reward for his play and to let exec and coaching see what they have in him. my bet is he will excel.
Also, use that time to assess who performs, what roles/attitudes they take,
once one of “the core” has been exchanged out. Maybe it’ll be a necessary adjustment to shake up what is often a stale attitude. Hopefully galvanizing. But something large is inevitable either way.