The newspaper report may not have said what the cabin crew actually said ... But the 'remove high heels' statement has been around for decades so should be well enough known unless, as SoS says, another language was involved.
I keep my shoes on and fully laced throughout a short haul flight. On long trips, I wait until we are in the cruise before taking them off. As soon as we start descent, I make sure that shoes are on and ready to run across hot tarmac or cold wet grass. You have to expect that every trip will mean you leaving the a/c with the bare minimum.