No, that’s not the reason they think Roberts should recuse himself.
It is because he has a gay relative (cousin or sister, I think...female definitely) sitting in the court watching the proceedings, and it is seen by some as a conflict of interest.
If it fits the rules of recusal, then he should recuse himself. If it doesn’t, then he shouldn’t.
Why didn’t the lawyer for REAL MARRIAGE demand that queer friendly Roberts recuse himself, pointing straight at Roberts’ bull-dyke cousin.