Ok, they have the trademark, but how does it give them the permission to reuse or copy the original game assets, designs, etc?
Anyone can illegally take anyone's content and use it. It's not until the courts are involved you can't.
Some are just better funded than others, like Disney.
Likewise, lots of people seem to think that just because some IP has entered the public domain or it's "fair use" you won't get sued if you start using it. Of course you'll get sued. The plaintiff doesn't expect to win, they expect you to give up. I can already hear the sound of a thousand keyboards typing out responses to this how numerous jurisdictions have laws against "SLAPP" lawsuits.