A regulation 800 point army may have up to two operatives. Currently, both factions only have one each.
For this reason, I don’t think the first round of releases will be “complete” until two more operatives are announced, one for each faction.
So, with that said, seems like Lando and IG-88 are likely candidates from the OT. Tho, I’m not sure if the empire needs another bounty hunter. If we add Rogue One characters, seems like Cassian would be a perfect operative, likely also giving the bounty keyword to the Rebels. Not sure about an empire operative from that movie, tho.
Besides operatives, seems like we’re overdue for some more heavies. Again, an 800pt list allows for up to two heavies. However, I don’t think the same logic applies in terms of the game not being “complete” without them. It may not be ideal, but you can run the two heavy limit with two AT-STs or two Airspeeder. Obviously, you can’t run two Bobas or two Chewies.