I don't think the 'shield for 12 weeks' or 'shield til September' were ever meant to indicate a time span in which it would be all sorted .... these advisories will be modified and extended(or ended) dependent on circumstances.... we can't expect to impose a fixed timescale up front on a fluid and unprecedented situation.... if ever there was a 'play it by ear' situation it's this ....and I'm far happier seeing fluidity than dogma right now.
K