It is highly unlikely that that is what they meant.There's a lot of discussion about the new (in England) requirement for EICR for rented properties. Apparently the legislation is worded to require that electrical installations must comply with current regulations rather than complying with whatever was current at the time of installation/modification.
If it IS then a huge amount of work will be required and a lot of properties will be off the market for some time.
Not exactly, that is the case for all EICRs but it does not constitute a "fail" (if that is the word you want to use) as far as the EICR is concerned.So in theory a rental would only pass an EICR today if a metal-clad CU was fitted (and everything else complied with 18th edition).
It will mean that the property is 'satisfactory' (if it "passes") although items may not be to the 18th requirements.
Whether this will prohibit letting remains to be seen. Obviously it should not.