Wait, so not only did Snow and Charming meet Captain Hook in past EF, but Snow was pregnant with Emma at the time?! What the heck?! And why didn’t Snow recognize Hook when he lied about being a blacksmith in S2? Let me guess: memory potion!
Technically Snow and Hook did meet before during the altered timeline in “Snow Drifts”, but Hook’s face was hidden in the shadows, which explained why Snow wouldn’t recognize him when they later met in Season 2. This scene in the musical episode, though, is either going to be explained via memory potion or it will be a large oversight that goes unexplained. What’s so hard about doing flashbacks that aren’t confusing or retconish? The writers make things more difficult than they need to be.