What they mean by "change the damage calculations of tanks"?

[Donjo]

If they nerf anything it will be gear, not the skill ceiling or rotation. Saying oh now we're just gonna be sitting there with our thumbs up our asses cause our numbers might not match brd/mch is really igorant.

This. No matter what the damage ceiling is for a Tank Job, we'll still press the same buttons in the same order and do the same things at the same times to max whatever DPS we do happen to have. A role already exists for those who place the majority of their enjoyment of the game on the value of floating numbers, and they'll go do that if they feel that Tanks aren't dealing enough damage to satisfy those needs anymore.

I get that people are scared that there will be a massive Tank Exodus when 3.2 hits, but I'm going to place my trust in SE one last time. They can figure out something that satisfies both the Tanky Tanks and the Aggressive Tanks. They've given themselves quite a long time to finalize and balance it, after all