The pre-Gillette, Molson Brewery owned Canadiens didn't negotiate a property tax deal before they built the current arena, oops, so the city had them by the chestnuts and squeezed them hard. They were paying more municipal property tax than all US arenas combined. So if the Canadiens were seriously insolvent to the point relocation deals were being negotiated, there would have been massive political pressure to give them relief (property taxes were over $8 million per year).
There has been some renegotiation on the taxes since, I'm not sure exactly when they got their first relief but at minimum 6-7 years ago it was cut down very low when the current ownership partnered with big developers to throw up a bunch of new officer towers on the property, no way they were going to make that mistake again haha.
The family controlled brewery had been seriously neglecting the club's business, so replacing them Gillette who himself was a good businessman, who in turn brought in competent executives. That along with I assume an eventual tax break, they got the financials in order, modernized the operations and improved the marketing a lot, greatly expanding revenues.
A funny aside, Molson Beer finally got their revenge on the city when instead of renovating their large 250 year brewery beside the port of Montreal, they decided to build a new one on the other side of the river in a separate suburban municipality. The company's lawyers and executives who fought that big tax battle with city hall must've been popping bottles when that decision was reached, long time coming for them.