Is that Gilbert remembers Mary's words about marrying only for love (they have to pay off somewhere!) decides not to get engaged with Winnie regardless of Anne, because even though she's lovely he wouldn't be with her for the right reasons. Then he goes to give Anne her pen back, and she's like great at least one bit of the note you remembered, and he's like "what note?". And maybe she gets to tell him how she feels.

The only thing is that if they get together so early it means they will definitely split up before being endgame if there are more seasons, because they're so young and in the books they don't get together until later. I don't really mind in honesty, it's a bit of a modern spin on a slow burn.

I hope this is how it goes, because the other option is that he does get engaged with Winnie, and it would be ending on a really sad note since it's obvious that while it will give Gilbert great opportunities it is unfair on everyone.