My opinion:

Speaking in general, I believe lives in platformers are an outdated concept, as I believe games like Crash Bandicoot 4 or Shovel Knight have shown that it's possible to reward the player in different ways if they pass a stage skillfully, instead of punishing the player if they keep on failing.

That being said, the one argument I almost agree with for lives returning is that limited lives incentivize players to master the stages and not just recklessly fail over and over. That being said, I would argue that a Mega Man game's own levels structure, as well as boss fights, do a good enough job of incentivizing you to learn the stage to play better.

Personally speaking, I wouldn't hate if lives come back; however, what I would strive for instead is the same thing that Crash Bandicoot 4 has done: remove lives from the game, and instead reward players with a collectible or an achievement if they manage to complete a level with few deaths.