U/C managed migration regs

I posted in your news section when the Universal Credit managed migration regulations were published earlier this month. Though it doesn't bother me personally, some have posted querying if "Legacy Benefits" claimants, upon submitting a fresh claim to U/C under the managed migration regime, will be subject to a fresh WCA medical. I noted some commentators were concerned they might have just had a WCA and then possibly be subject weeks or merely months later to another one. I couldn't find a clear answer when I read the regulations and wonder if Steve Donnison or any of the B and W team have studied in detail the regulations with regard to this question.