It's also fairly safe to assume that there were no plans for Sera to be in a relationship at any point, so no plans needed to be changed to accommodate the pride merch.
And also his existence confirms Jesus's existence and that he was someone of Heavenly importance, though I suppose it doesn't technically confirm whether the Christian or Muslim interpretation is correct (I think; I can't remember whether Muslims claim the apostles misinterpreted Jesus who was totally preaching the exact same thing as Muhammed or whether it was later Christians who messed it up and the apostles were all good Muslims).
Muslims (usually) blame St. Paul for Christians worshiping Jesus. If you read the Quran, before Allah decides to bring Jesus to Heaven and accidentally start the world's largest false religion by tricking everyone in to thinking that Jesus was crucified when the Quran says he wasn't, Allah promises to make Jesus' followers uppermost.
Of course, when early Muslims didn't have much access to much of the Christian world or scriptures, they basically assumed they were dealing with some rogue heretics who thought Jesus was God, and that this wasn't in fact the whole shtick of Christianity. Even in older Islamic commentaries, some commentators specified that Jesus' followers being made uppermost
obviously would refer to the disciples, and especially guy's like St. Peter & St. Paul.
Then as time goes on, Muslims realize that this can't be the case, because all these people that Allah made uppermost are committing shirk, the only unpardonable sin in Islam. So the theory goes, that it must be St. Paul who corrupted Christianity, because his letters are very explicit about Christ's divinity, and he wasn't a part of the original 12 disciples, but he's still early enough to start the change early.
I think this doesn't really work if you take the Quran seriously when Allah says he made Jesus' followers uppermost, because that means either the Trinitarian Christians are correct, and Muslims should therefore apostatize and join them, or Allah made Jesus' followers the top of the totem pole, only for some random Jew to come along and personally undo it, within a couple of years, making Allah incredibly impotent.