His contract wasn't renewed, not really fired. Dubas looked/sounded burnt-out at the end of year presser.
I think he got out at the right time. He has a great regular season record as GM, so he'll easily get another GM job when he wants one. Contracts are ending in the next 2 years for almost the whole team, the prospect pool is about barren, and there isn't a lot of draft capitol; so there is cleanup to be done. That falls onto the next guy to clean up and not him.
Whoever ends up as TOR's GM is won't be able to do anything without 5 people asking about the future of the big-4. I mean GMBG got butthurt and went off when asked about Fiala and Talbot last year. Could you imagine what he would do in the TOR media circus?