I agree, Christians (by that I mean Orthodox in belief and holding to statements of faith like Nicaea) will be underground. The Catholic Church is the most visible, and thus, the easiest target, but it would easily extend to Orthodox Churches, Traditional Orthodox Protestant groups (PCA, Missouri Synod, Reformed), and Conservative Evangelicals. The Catacombs may come back.
I don’t think that they should be pictured as a couple....however they should be allowed to remain, as individuals, parish members. The church is , after all, here to minister to sinners....no?