[eskathos]

Is there any way for a company, Lego in this case, to adopt a fan mod or remake, to make it legitimate IP/copyright wise?

[Krutonium]

Absolutely. They just have to license it, and that license can be for a nominal (think $1) cost.

That said, Lego doesn't own the game, so if it came down to it, they could strip all the references to "Lego" from it and probably be fine.