Please add support for Multibranch Pipelines. Unlike Freestyle and Pipeline jobs these aren't supported yet.
Thank you for the suggestion! This is part of our roadmap and we hope to release it in the not-too-distant future.
For what it's worth the https://plugins.jenkins.io/cloudbees-bitbucket-branch-source plugin works very well for using Bitbucket Server with multi-branch pipelines. It uses the Bitbucket Server native webhooks support.
Will be part of upcoming release 1.0.5