I'm thinking Phoenix ult might be increased to 7 points like they just did with Reyna, and I think one of the controllers Viper, Astra or Brim will get a bit of a nerf. I don't think anything too noticeable will happen except for the obvious duelist nerfs until at least a new agent is added, and I think noticeable buffs won't be too common since they're trying to reduce utility overwhelm a bit. Sentinels will be stronger when duelists become weaker, although I think they should revert the Vyse flash changes.
In general though, nerfing certain guns would be more of a priority to me than agents, there needs to be some sort of slight outlaw and odin nerfs.