I explicitly said upgrading the talent positions and upgrading the bottom6 can be done in parallel because I largely agree with you. But it's much harder to upgrade the top6, so if we want to improve the team overall, some swapping and jostling the bottom6 is to be expected. Don't forget that Bergevin never really managed to upgrade the top6... that was his problem.
But you keep saying things like if we want to improve the team overall we also need to improve the bottom-6 and not just the top-6. And that's not really true, nothing we do to the bottom-6 matters until the top-6 becomes good, and since the bottom-6 changes for all teams every year as is the nature of depth players there's really no point in upgrading it now unless we think the top-6 is also getting fixed. If we upgrade the bottom-6 today but it takes another 2 years to fix the top-6 those bottom-6 upgrades will have already run their course and will be getting swapped out.
And if you agree that we can't accurately judge the bottom-6 without a good top-6, then there's no real point in "upgrading" guys since you might be "upgrading" a guy who would actually be a good bottom-6 player for us when the top-6 is fixed.
So sure upgrade the bottom-6 to your hearts content on the Armchair GM tool on capfriendly while it's still there, but don't expect it to actually matter in terms of how many we win and don't be surprised if a guy you move out goes on to have a strong impact when put in the right situation with a different team.
I'd also point out our biggest problems in the bottom-6 is the big contracts to Anderson, Gallagher, Dvorak, Armia. So sure getting rid of bad contracts is a good thing to pursue, but for that reason it's actually going to be difficult to upgrade the bottom-6 this offseason.