Removing the agent(s) does not remove the expired license(s)
Licenses has been removed succesfuly by running the following commands, as described in the KB article:
Veeam.Backup.Manager.exe -removelicense vaw
Veeam.Backup.Manager.exe -removelicense val
Luckyly, all VAW and VAL licenses were trial licenses, as license type (perpetual, trial, etc) cannot be specified.