Sabres aren't retaining salary for 5 years lol

^ what he said

Note, e.g., Kessel deal from TOR to PIT. And he wasn't injured like Eichel.

Some people do not understand value.
It may not be the GM who decides not to retain, but I would.
Imagine a top line of Skinner - Strome - Buchnevich
Strome may produce enough for a GM to consider picking him up at the TDL for a first with additional retention.
Is Reinhart is traded Buchnevich would make a very nice replacement.
If he was traded he would bring back a mid first and a decent prospect who has the value of a first.
Add Kravtsov and the Sabres could be receiving nearly 6 first round draft picks for Jack (one for Strome, Kravtsov, two first round picks and two for Buchnevich).
Even with $2,000,000 that is a huge return.
Even an idiot as KA would be a fool to not make that deal.

EDIT:
Kessel is not Eichel but he did help the pens win two cups and the return for him was nothing as good as this return.

Second EDIT:
BTW that trade punches 4 tickets for the Sabres. Center, RW, GK and picks.
It fills needs unlike trades that are offering defensemen.