Assuming no other changes I would go with:
Tatar - Danault - Gallagher
(one of the best 5 on 5 lines in hockey)

Drouin - Suzuki - Anderson
(Drouin / Suzuki worked well in playoffs, Anderson replaces armia)

Byron - Kotkaniemi - Toffoli
(KK and Tofolli aren't the best skaters, speedy guy like Byron will be a good compliment. Byron and Lehkonen are pretty interchangeable, but MTL should probably try to boost Byron's value to trade him before his contract hurts them, and maybe it will help with Lehkonen's negotiations if he plays a 4th line role. At the end of the day play the best player of the two though.)

Lehkonen - Evans - Armia
(What a luxury to have these guys on the 4th line).

Romanov - Weber
(Really hoping Romanov impresses in camp. Mete played well here, Chiarot was great and then pretty average as the season went on. Romanov would be ideal.)

Edmundson - Petry
(This sounds like the plan from Bergevin)

Chiarot - Mete / Kulak / Juulsen
(The last 3 battle it out for the last spot on defence, Fluery doesn't need waivers and he isn't a clear upgrade over any of these players, playing 1st pair in Laval would benefit him)

I would prefer Armia in a more offensive role. Drouin-KK-Armia worked well

Not sure Anderson is a PP1 player. Not sure Romanov has the upside to be a PP quarterback too. Petry has the PP1 blue liner

Finally someone that gets it... I really like these D-pairings too btw, hopefully Claude goes with them and they work out.