You're right, the time-jump does seem rather illogical now considering the timeline. It definitely only meant to be part for Dean's lack of storyline to angst about his now former domesticated life he tried to have and about having his brother back. Though it makes me wonder had they not done a time-jump would all of what we're learning now have had the same impact? I can see how it could have been used as an idea, but that idea fell short when they didn't think it all the way through when you take into account those holes.

I'm actually wondering because at Chicago Con Richard gave no indications whatsoever that Gabriel was even rumored to be back this season. I know the actors cannot say anything of spoilers regardless, but it struck me as odd that there wasn't even a smidgen of a clue somewhere. Even though it has been confirmed that Gabriel will be returning this season. So, idk.