I have had several clients who were using BitBucket and wanted to integrate EWM. The story is not good...

Basically Atlassian has stopped on prem BitBucket implementations, and has severely restricted their Cloud implementation, effectively preventing almost all integration. Even their top tier enterprise level BitBucket gives you just very basic integration.When my clients contacted Atlassian Support they were told that they could integrate with Jira and Bamboo and that anything else was in an enhancement request - when they checked the request was several years old and inactive, but had a ton of comments from their users. So basically it's in high demand but Atlassian has no interest in implementing it

All my clients have since switched to GitLab - their basic cloud tier gives you a GitLab supplied native integration and web hooks, and their on prem gives you complete server side hooks. Pricing worked out cheaper too