When I create a tag on Bitbucket Cloud the webhook notify Jenkins for a new tag. But the jenkins plugin does not handle it has a SCM event of kind tag but as branch created event.
The PushHookProcessor should be changed (line 165) to check of which kind of event is the notification.
It is also needed add date to the com.cloudbees.jenkins.plugins.bitbucket.api.BitbucketPushEvent.Reference.
I also suggest to configure the ObjectMapper in payload parser (JsonParser) to use the ISO8601DateFormat that comes with jackson instead the custom.
Use a specific deserialiser for BitbucketCloudRepository.updatedOn where BB sends an invalid ISO8601 date format (6 decimal for milliseconds field instead 3 that cause date parse error)