It's not weird or peculiar at all. Lego Marvel Game = Money. WB and Disney like money. The competition between the two brands does not mean that their respective owners would pass up an opportunity to make said money. Also, WB has used Disney IP on at least two of these games already (Indiana Jones and Pirates).
EDIT: Yeah, I see that I'm way late to the party on this.
XCom Enemy Unknown somehow managing to meet my lofty and unrealistic expectations (as a huge fan of the original with firmly fitted, rose-colored, childhood-nostalgia goggles) and keeping much of the feel of the original while streamlining play (not having to buy and track weapon magazines individually for your entire platoon of commandos, for example).