COVID played a massive role in the Blues not being able to hang on. No chance that they let that many core players walk if they're not dealing with a flat salary cap.
I might be in the minority, but I don't agree that the flat cap was what led to core players walking.
Maroon got $900k from Tampa in the summer of 2019. That was a roster decision, not a cap decision (and it was well before anyone knew a flat cap and COVID was coming).
There was a 9 month period where we could have signed an extension with Petro before COVID hit. Instead, we brought in Faulk and committed $6.5M x 7 years to him. I don't want this to lead to another re-litigation of the Petro decision, but I think that we can all agree that it wasn't the flat cap that made us unable to keep him. This was very much a should/shouldn't decision and not a can/can't decision.
We lost J-Bo to an unpredictable injury, not a cap thing.
Schwartz got $5.5M x 5 years from Seattle in 2021. A week earlier, we had acquired and signed Buch to an AAV of $5.8M. We gave slightly more money to a younger player of the same position. I think that this was very much an unwillingness to allocate that money to an aging inconsistent player than it was a casualty of the flat cap.
Is Dunn considered part of the core? If so, we lost him because we exposed him after giving Krug $6.5M x 7 years. Certainly not a flat cap thing.
Sunny played 2.5 more seasons here, but had major injury issues and wasn't living up to his contract. He was moved in a deal for a more expensive player (who was extended). I wouldn't call that a flat cap casualty.
Perron played 3 more seasons here after the Cup win and all sides agree that we offered him a fair AAV on a 1 year deal, but that the issue was term. I don't think that our concerns about term given his age would have been any different without the flat cap.
ROR, Tarasenko, and Barbie were all here until the team imploded and they were traded as rentals because the window with them had obviously closed. Bortz stuck around even longer.
Binner, Schenn, and Parayko are still here.
Bozak, Steen, and Gunnar retired as Blues.
That's more than the 'core' but I think it demonstrates how little the core was disrupted due to the flat cap. The flat cap made it harder to supplement a good veteran group and I think it did contribute to our downfall from contender status. But I don't think that it led to the core group being slowly dismantled.