I think Dubas was fair with him. I think he was respectful, I think he told him what the team could do, what they thought he was worth, and where they thought he would fit. I think as a player, he respected Dubas for being upfront and not being insulting with an offer. I think Dubas building a team that finished with franchise records had an impact on Gio's decision to take less to sign with a team he thought could win some rounds.
Similarly, Lou's negotiation tactics of being insulting left bad tastes in the mouths of several core players that Dubas had to repair relationships with. For example, Marner was hurt Lou didn't view him as a franchise piece and cost him millions in bonuses he hit after refusing to give them. It resulted in Marner wanting to take every penny, after being told "it's a business" from Lou after being bent over.
So I think Dubas learned from that, and negotiates from a position of 'this is what we can do, this is what we can offer you aside from money' and it has worked well for him. Like everything, it was not in a vacuum. I would trust Dubas to re-negotiate the cores contracts again. He's learned a lot and managed to find ways to get players to take less.
Hope not, would be the biggest mistake the franchise has made in some time. But I am sure you will be happy to hire more Burkes and Nonis types to overpay David Clarksons in the name of grit