Do we get to edit or delete the objects in Glacier vault lock post its retention period ? is it similar to Object lock in Compliance mode except that it is Glacier storage class or type
It’s different to compliance mode in S3 since Glacier Vault Lock is actually a policy that once set governs what you can do to objects for the life of the vault. It is up to you what you want to restrict and you can out in place policies that behave like compliance mode object lock for S3 Object locks.
If you wanted to ensure that objects can never be deleted for a year your policy would deny deletes until the object has been archived for less than 365 days. See https://docs.aws.amazon.com/amazonglacier/latest/dev/vault-lock-policy.html#vault-lock-policy-example-deny-delete-archive-age. In this example, after 365 days you can delete the object.