Outlook on Mac is implemented differently than on Windows. Outlook from Mac uses a single database which indexes smaller threads of data like contacts, and signatures stored in data records. If you have multiple accounts everything is stored within this one database.
This differs from Windows where each account generates an individual
.pst file. When you unlink an account on Windows, the .pst with all the data for that account will persist and can be relinked to simply by adding it back to Outlook.
As OS X has all of the data residing in one database. Removing the account removes its data from the database and you shouldn't have to track down a
.pst file as you would in the Windows implementation.
There is not even a way to archive and maintain the contents of an Outlook account in Outlook 2016 for Mac as there is in the Windows version.
Refer to this post on AskDifferent.
Note: I have deleted an account from Outlook for Mac 2016 before and it basically disappears from existence. I couldn't say if a computer forensic scientist could rebuild this information, but the average user won't be able to get at it as they can with the Windows version.