I don't think that trade would happen right now, I think that trade would happen at the draft.
Personally if Hagens makes it past Nashville, I'm not sure who I see taking him in the top-10. Philly doesn't make sense after adding Zegras and I feel like Boston goes O'Brien or McQueen over him. Hagens would be pretty redundant on Seattle and Buffalo too, I don't think he makes much sense for them.
I think Nashville and Boston are the only teams in the top-10 that Hagens makes sense to, after that I think he would slide to #11 where the Penguins would pick him. My top-7 right now feels like:
1. Schaefer
2. Misa
3. Frondell
4. Martone
5. Desnoyers
6. Martin
7. O'Brien
I feel like Hagens slides to #8 or later, but I'm not sure who between #8 and #10 will take him. I don't like any of the fits there.