Anything can happen over the off-season: injuries, FA defections, retirements...
If you (Bills management) believe that your team has the ability to win the division or be a Wild Card team, you must make this move. JP's development may be slowed a bit but the team just can't continue to throw away opportunities.
If the D continues to suck and they continue to lose games, then you can put JP back in for the second half of the season to get his OTJT. However, if you beat the Phish and the Jests in the next two weeks, you're right back in the hunt for the division.
Now's the time to make the move. 7 of 15 for 75 yds and a pick ain't gonna do it. I say that if we (as fans) want the Bills to make a run at the division, we applaud this move. Way too much can happen between now and "next year" to waste the chance.