The way I see it...regardless of whether they bring back Rivers...Ballard should still be looking to draft the next long-term QB. That would allow for that player to sit and learn for one season...if that is their intention.
If Eason was that guy...then I think there would really be little reason to bring back Rivers...because he has already sat for a year behind Rivers. You would just have Eason take over and then sign a Fitzpatrick type-vet as backup/insurance...and go from there.
Without many roster spots open to draft picks...I think you could see Ballard get aggressive in this upcoming draft...assuming there is a guy he likes.