Only thing that kinda irks me (heavy emphasis on "kinda") is it's Foligno's return, and I don't really think that's fair to usurp that with Nash's retired jersey ceremony. If they wanted to do it against Boston, they're back in town less than a month later on April 4. Or do it when NYR are in town if it needs to be against a former team; he's much more associated with them than Boston anyway.
Regardless, I have no problem with the decision to retire his number, both in a vacuum (I think he's worthy enough as is) and within context (there's really nobody else close to him in the franchise that's currently retired, and with Bob's/Cam's departures probably preventing them from reaching that "retired number status", there may not be anyone else who'd be more worthy of a retried number than Nash for at least 15 more years [Werenski's the only player on the current roster who I think has the chance to surpass Nash in CBJ individual career accomplishments. Maybe Sillinger, but in that case, you can change the "at least 15 more years" to "at least 20 more years"]).
I'm also a person who doesn't mind "unconventional" jersey retirements if they're a significant/important person in the history of the franchise. It wouldn't even bother me if they announced they were retiring Shelley's number. It's not the Hall of Fame. Each franchise is different.