At this moment, the Last Activity information is available in the .csv file generated by the Managed Accounts export feature (Export managed accounts).

However, in some specific cases, there are users who aren't accessing any products and can be using their accounts to:

• Access the Atlassian Community
• Handle administrative tasks (like an Organization or Site Administrator) or billing.
• Create tickets at https://support.atlassian.com/contact/
• Etc.

When using the Export to validate if a user can be deactivated, admins can erroneously deactivate one of those accounts.

Suggestion

Provide the Last Login date information in the export file. 

Workaround

Use the Organization Audit Log, filtering by the activity Logged in to account