It has happened. There have been threads on here in which it has been reported. So - YES - it has been shown to be correct.
HOWEVER, at the moment it is not widespread and I have not seen one bank come out and state that it is their policy to close non-resident accounts....... Another HOWEVER, you cannot open a new UK bank if you not UK resident. Take that concept a stage further and a logical next step would be to attack low-hanging fruit i.e. existing accounts with an overseas address - or where non-residency has been declared. Compliance is the reason cited by the banks, or more specifically "much higher costs of compliance" where non-resident accounts are concerned.
Everyone should have a WISE account as a back up.