JJxvi said:
It happens repeatedly before the big battles to determine who is on what side throughout the series so far. Stark-Frey and Tully-Frey marriage is negotiated immediately before hostilities. Renly Baratheon-Tyrell Alliance occurs before hostilities. The Lannister-Tyrell alliance is negotiated immediately after Battle of the Blackwater to secure an alliance in the ongoing war. Tywin wants to marry off Cersei immediately. There is political intrigue among Lannisters and Tyrells over who will marry Sansa, etc etc etc. Diplomacy occurs almost exclusively through marriage repeatedly.
I'm not "excited about some marriage proposal," I'm just saying its really stupid that they left that out and it would be even dumber if this meeting and an alliance happens without it being even discussed. It makes me think they either really are going to spring that on an audience they hope will be unsuspecting, or they are just too lazy to think out realistic motivations for their characters.
Fine but those are allegiances between longstanding families with lots of kids to marry. The Lannisters and the Tyrells forming an "alliance". Now you've got 10-15 more noblemen on each side to support your alliance. But tell me what great families are Jon and Dani joining together? Jon still isn't a Stark and he only has one half-sister that has already been married off twice before. And Dani, likewise has already been married off before to someone who ended up murdering her only living relative, Visirius.
I guess it is pretty obvious that I am on the complete other end of the spectrum from you, but I personally think it would be insane for them to even bring up a marriage proposal right now. This isn't a situation where their parents are trying to barter them off to gain some strategic advantage for their houses. Dani made alliances with all the other groups without marrying any of them, I imagine she'll expect the same from Jon. And Jon is only, what, two years removed from vowing to never take a wife? Clearly he's fine moving on from the Night's Watch vows, but the point is that he is far removed from that side of diplomacy.
Take a look at all your examples, Robb-Frey: fail, Cersi-Laurel: fail, Joffrey-Margery: fail, Sansa-Joffrey/Tyrion: fail, Renly-Margery: fail, even Cersi-Robert was a failure. Just because the old people did it doesn't mean it was a good idea or that Dani and Jon (whom neither ever really grew up in that kind of society) would follow in their footsteps.
Edit: remember, ALL those arranged marriages were arranged by a parent. Even Robb's was arranged by Cat, I believe. Until he broke it and Edmure Tulley said he would take a Frey wife in his place. Other than that it was Ned, Tywin, and Olena setting their children up for their own purposes.