That’s not normal. Foster placements are almost always intended to get the child home. The parents don’t stop being the parents and usually have a list of conditions to follow, this might be drug testing, improving the home, etc.
It can be quick, a couple of weeks, but it’s often slow. With having to get off drugs they have to do X amount of weekly drug tests to prove they’re long term clean, 6 months isn’t uncommon for serious addicts.
This baby was intended to go home and they knew it.