I really dislike the lack of continuity between Wildlands and other games of the franchise. No mention is made of the events in GRAW 1 or 2(NAJSA, US intervention in Mexico,etc), which would have really influenced the situation in-game, considering they took place in 2013-2014, while Wildlands is presumably set in 2017. Santa Blanca is a Mexican Cartel, and El Muro is ex-Mexican SF. It'd have been much better if the Cartel or El Muro had some connection to the events of both GRAW games. Maybe the Cartel is made up of many of the former rebels, or maybe El Muro took part in the coup in GRAW 1 or even fought alongside Mitchell and the Ghosts in Juarez.
It seems we've also stepped back in technology, despite the game taking place 3,4, or more years after GRAW. No CrossCom tactical glasses, no advanced body armor with proper multicam, no caseless rifles, no XM8s(gun's a staple of the series IMO). I can sorta understand not getting the classic Ghost uniform from GRAW(or similar equipment) in the base game because we're supposed to be operating clandestinely(although we can still throw on heavy body armor and American flag patches), the CrossCom would be great to have. We already have plenty of high tech weapons rolling around Bolivia, so XM8s wouldn't be out of place. The MR-C might be slightly more so with its caseless ammo, but high tech combat is the Ghosts' specialty(and they're already rocking portable drones like the ones from GRFS). The CrossCom would have also been a lot better than the current method of squad management we have now, which is god-awful.
Hopefully Fallen Ghosts can at least introduce some more classic Ghost Recon equipment. Since Fallen Ghosts takes place in the wake of a presumably not-covert rescue mission, hopefully we get some more overt gear, as opposed to all the covert/low-profile stuff currently in-game. More heavy vests, helmets, and military fatigues would be great.
A GRAW1 costume or (better yet) customization pack would be great as well. Not GRAW 2 since ACU is gross. On another note, making GRAW1+2 and GRFS backwards compatible would be really amazing