Since he was recently racing and did not get a gradual let down, you may be dealing with body and leg soreness for some time, IMO wait and see is an option here, wont worsen anything and Dr Green may do her magic with him simply moving regularly and naturally over time as he physically recovers, rebuilds and finishes growing with the now available calories not diverted to staying in racing shape.
Overall, sounds like good news, might want to use Bute for awhile to help reduce the likely considerable inflammation as well as help him move without favoring something thats sore.
Give him 60 days or so, thats a couple of shoeing cycles and lots of unforced steps. Reevaluate then if needed.