Based on recruiting rankings, ratings, high school stats, division 1 offers, college experience (both in terms of practice time, games, etc), POB should be considered a 'decent' QB by any reasonable measure. Most on this board were pretty positive and excited to have him accept our offer to come play for DONU as I recall. He wasn't a speedster nor was he considered a top 'dual threat' QB but he was not an invalid and or crippled and incapable of moving around and running at least a little bit.
Based on the foregoing 'facts' or assumptions, then it is arguable that our QB room is not 'empty' as he was apparently running no better than 3rd or 4th on the depth chart after about 7 practices. (not enough to dump him off the roster in my view but then I don't get to watch practices as these coaches do). It seems that POB was willing to give this offense a try as he would have likely transferred out in January in time to get spring ball at his future home.
I don't see any real value in recruiting a grad transfer in here this summer UNLESS the coaches are desperate or feel they really have only one true 'starter' and one marginal backup on the team. If so, then we need to either move somebody already on the team to a back up role as an emergency guy if nothing else or we need to strongly consider the offense we plan to run this fall accordingly. If we don't have QBs enough to run the Frost offense, then we better adapt to the available talent.
I would tend to think, based on the above, that Frost feels we will have QBs on the team that can run his offense sufficiently, without POB or he'd still be on the team and he would not have been 'let go' via demotion on the depth chart this quickly. This is a good sign to me.
POB was not a 'bad' QB by most measures. If Gebbia and the others are better, then things look promising to me.