I really enjoyed the heist missions in GTA V.. specially enjoyable were the heist preparation missions which were a clear step up from the previous GTA style of "drive here, and kill everyone" set up..
All that being said I hope Wildlands features some level of buildup to the "Big" missions... I hope they diversify the missions not just by location but by goal...
I wouldnt mind doing some actual preparatory "Recon" missions in a Ghost Recon game.
I like the idea of having to recce a target before striking but I don't necessarily think it should be a mission, I'd rather it was just something you can choose to do in the open world. Hope you get what I mean.
I really enjoyed GTA:V as well and even though the two games will probably be very different I think there are a lot of lessons to learn from GTA.
Overall I'm hoping for Wildlands to have absolute freedom in how you choose to tackle your missions, something I felt GTA was lacking.
As we know that there is no limitation of distance beetween the members of a squad, it would be nice to make preparation missions in groups you decide yourself. What I mean it's without any menu.
You can say to your squad "le'ts go make two groups of two to prepare this mission" or "OK guys one go for Intel and the three other we try to get this [insert an objective]".
And then players finish the final goal together.