Setting their expectations at +7.2mil and then trying to lowball them for +1mil less would be a great way to burn bridges. You're not going to be able to buy any UFA years from Cirelli or Sergachev @ 6-6.5mil
And that's your opinion. Their qualifying offers are 5.76, neither of them are likely to get more than ~6.5 in Tampa. If they want some number like that, then moves will be made. Neither player is worth more than 6.5 really, and has been shown in the past, just because other teams make poor salary decisions with players not worth what they got, doesn't mean Tampa will be making those same mistakes. You can spin this trade as being good for Tampa all you like, but it's not. From both a positional value to actual contract value standpoint, Tampa has no reason to do this.
They will qualify them for close to the 5.76,and negotiate from there. If Serg's camp comes out demanding laughable 8+ numbers and Brisebois can't get them to an actual reasonable number, oh well, there won't be any shortage of teams interested. I expect Brisebois will look to get their extensions in place as soon as possible after this season to avoid contract issues next offseason(and several of Tampa's players have signed their long-term deals with a year left on their bridges, so it wouldn't be surprising to see at least a couple of these guys do the same).
Most in Tampa realize that Palat has a decent chance of walking or that he'll be re-signed and Killorn traded this offseason. What Tampa won't be doing is moving 2 of their young core pieces for a worse defenseman and a winger(albeit a good one) that doesn't fill any hole they have(without creating a bigger one elsewhere) nor provides any meaningful cap relief. Bertuzzi isn't re-signing in Tampa for any discount as a ufa, and I'd guess the team wouldn't want to deal with any of the possible vaccine issues he may bring either.
Tampa won't be "burning any bridges" in negotiations either, as all 3 of these players have been with the team a while and understand both the cap situation and how the team handles contracts. I'm sure there may be some back and forth over the final numbers and details, but if they want to stay with Tampa, they will knowing they'll still receive a large amount of money and continue to be part of a great team and organization. If their primary goal is just making as much as humanly possible regardless of where they are, sure, I'm sure some team could OS them out of Tampa. I don't see it happening as again, if JBB can't make it work(likely this Sunmer/Fall), he'll trade Serg for multiple picks/ready to go ELC types, which also helps Tampa both now and for the future. The trade isn't good on Tampa's end for multiple reasons, and since Brisebois is a good GM, can't see him ever doing something like this.