I found it just a very odd choice in general(Debra's crush on Dexter). They hinted at it in the first two episodes, but seemed to have dropped it. (I think in the first scene they're talking and there's somebody in the background holding a donut with a banana through it).

I think the point was that that Debra arrived thinking she had a secret to unload while discovering Dexter's ultimate secret. To me, it's just excessive because... where can you go with it? They're going to play it deadpan as to not ruin the characters, which I imagine just ending in a train wreck.

However, if they begin the next season at the EXACT moment of the discovery. Play down Debra's crush, and whatnot. They can lead to sort of a tense allyship that ends in a manhunt of Dexter that could wrap up the series over the next few seasons. Or something, cause they've DEFINITELY gotta find a way to wrap this thing up.