"Reuse the existing tables" requires new Super User?

I’m reinstalling piwik so I can upgrade to 2.2.0. Using the update link in piwik times out so I have to manually upload the files for each update.

On step 5 during the re-install process I select “Reuse the existing tables »”.

Then step 6 asks me to add a Super User. If enter my existing Super User info it says that login already exists.

And I don’t see a way to skip having to create a new Super User.

What’s the purpose of having to create a new Super User? Shouldn’t my current Super User login be recognized?

Will creating a new Super User mean I have to update the token on all my websites?

I went ahead and created a new Super User, then logged in using my previous Super User credentials, and deleted the new Super User.

My API auth_token token (or Super User auth_token) stayed the same.

Not sure why the re-install required creating a new Super User though.