We don't currently have any policy against characters, Architect Entertainment missions, supergroup bases, etc. that copy or make homage to other people's trademarks or intellectual property. Reports of infringement will be noted, but no action will be taken*.
However, that does not mean HC will never have any such policy, especially if Homecoming Team finds itself in a situation where it is required to comply with a rights-holder's cease-and-desist or DMCA takedown notice.
(In short: it is fine now, but don't assume it will always be fine).
* If you yourself are an author, artist or other intellectual property holder and a HC player's content is infringing on that, please file a ticket with proof that you're the rights-holder, and we'll talk.