Is there a reason to deactivate but not delete old users from HubSpot?

Yes, always deactivate first. If user is deleted:

• Any scheduling pages created by the removed user will be deleted.

• Any social messages published by the removed user will remain published. However, if the removed user was the administrator for any social media accounts, you may need to connect accounts again.

• Any marketing emails created by a removed user will remain, but all user information associated with the marketing email will disappear. For example, no name will be shown when you view who the marketing email was created by.

• Any sequences, templates, and documents created in your account will remain; however, the removed user must have shared their sales templates prior to removal for other users to access them.