Adoption back to RU

We had an FST meeting today and this is the first time bio dad showed up. He was originally going to sign over his rights. He just let us know he'd like to work on getting his rights back and taking little one back in his custody. I've had little one since 2 weeks old, I got them straight from the NICU. Little one was born addicted and bio mom showed up more for the initial vists and bio dad has met him once for an hour. Little one is now 17 months and hasn't seen bio dad since 2ish months old. Bio dad got out of prison recently and is doing rehab for the next 9 months. It was for drug and burglary offenses. CW has already switched the goal to TPR I think she is still working on getting it approved. I'm not sure she's brand new and her communication hasn't been all that great since we switched to her. How likely is it that they will switch back to RU since dad is hours away at rehab and won't be done with that for another 9 months. Little one will be over 2 when they finally meet bio dad in person?