It sounds like they have extended the validity of the medicals for twelve months. Not certain though, did you do a re-medical? Or just the one?
At any rate it does seem to mean that there was a new medical certificate issued valid for twelve months (from some date).
Just to add, as far as the "Reassessment" is concerned - not for sure, but i think it might have been the Eligibility.
Whats your timeline?