After the pandemic

It's actually already gone .If it's no longer law to wear an exemption pass then the legal requirement to wear a face covering is no longer enforceable
The wording being
1) You do not routinely need to show any written evidence
2) You do no need to show an Exemption Card
3) Carrying an exemption card or badge is a personal choice and is not required by law
Source Gov.Uk

A lot of the information is currently being rewritten in preparation for July 19th and is changing from law to advice.