The subject says it already:
Can Bitbucket extract information about a JIRA issue from the Git-Notes?
Because: If a JIRA ticket is mentioned in the commit message, then it is displayed once in the column "Message" and also in the column "Issues". That's redundant information.
Benefit: You have the possibility to link commits to JIRA issue additionally or with more JIRA issues together.
But JIRA issue page also have to extract the information correctly - which it doesn`t do.