I think they know people are very interested in how baby Henry came to SB, so I’m sure we will see that story. It is likely it could be linked to the HO, as the timing of the story falling in season 3 would then make sense, just as not seeing week 1 of the curse didn’t make sense until they showed the “outsider”.
It is fun to go back to season 1 episodes and see all the little things they either foreshadowed (or cleverly ran with in writing new episodes).
“If I had a world of my own, everything would be nonsense. Nothing would be what it is, because everything would be what it isn't. And contrary wise, what is, it wouldn't be. And what it wouldn't be, it would. You see?” -- Lewis Carroll, Alice's Adventures in Wonderland & Through the Looking-Glass