Amazon OpenSearch 2.11 is the only officially tested and supported version for Bitbucket 9.x.
Amazon has not announced an end-of-support date for 2.11+ yet, so we haven't yet planned to add support for newer versions. This does not necessarily mean they are incompatible, but rather that they have not been officially verified by Atlassian. Therefore, using these versions might carry some risk of encountering untested issues.

This feature request is a suggestion to test the newer versions of Amazon Open Search with Bitbucket Data Center.