I don't think the streak will factor into the decision. The more likely factor is, how cautious do the Cubs want to be with their best trade candidate? I think they roll him out there for at least one more.
Could that have been Ryan's last inning? He's at 80 pitches. And if allowed to continue, would it hurt his 32 scoreless innings performance? I would sit him, but that's just me.
....and they did.....Hope he stays and finishes strong.