[Mediterraneo10]

When the new apps and digital certificates were announced, being able to revoke certification at any time was touted as one of their major advantages over traditional vaccine certificates. This way, if a new variant arises that preexisting vaccines don’t protect against, or if a state wants to enforce annual booster shots, they can just invalidate older certificates by updating the database entry to which the QR code points.

[account42]

Neither new variants and boosters are reasons for revokation as both are better served by information about the vaccine administered and a timestamp.

[mercora]

if there is a new vaccine required or some follow up procedure or whatever it would make more sense to hand out a new certificate that validates this fact instead of revoking the old one that is actually still perfectly able to validate your previous actions. In fact it might be very beneficial to keep them around to give approval to another step like lets say you will only get that booster shot after you are able to present validation of your vaccination or similar... invalidating these certificates by giving them a date until they are valid is very easy without explicitly revoking certificates.

[CaptainZapp]

At least here around I never read that argument. Given that it's initially valid for only 6 month I don't think that's really an issue.