Is this a copyright troll or something?

This seems awfully suspicious. Only games with specific keywords have been struck down. For example, most of the Sonic games, but not Shadow the Hedgehog or Mean Bean Machine. Another example is that a ton of Mario, Pokemon, and other series Nintendo owns are gone but Wario, Kirby, Star Fox and other game series they own or share rights with (like how they own a third of The Pokemon Company) are still up. It seems strange how selective this whole thing is. It might just be a copyright troll but I don't know if its possible to tell or not at this stage. Additionally, why would the ESA specifically go after the Mega Man games? Capcom I could get, but the ESA? Last time I checked, the people who made the ESRB aren't exactly employed by Nintendo, Sega, Sony, Capcom, etc. This all just seems odd.

Vimm's Lair has been asked to remove many games from The Vault on behalf of Nintendo, Sega, Lego, and the ESA. While most of these games (and the hardware to play them) haven't been sold in decades, ultimately it's their prerogative so these games are now gone for good.