Atlassian Account Upgrade- I am Jira proj admin- what do I need to do

[Tony Wallace at Cray]

Received this email- 

{quote}Last year we introduced Atlassian account, which allows your users to log in to any Atlassian Cloud product with the same email address. Find out more about Atlassian account.
We'd like to let you know that starting 24th April 2017, we're upgrading all users on chapel.atlassian.net to an Atlassian account. Your users won't be logged out. The next time they log in, they'll go through a simple email verification process that takes about 20 seconds.
To complete the upgrade, we need your help with a few things. Visit the Atlassian account page in the site administration and complete the steps on the page. You can then click enable Atlassian account.{quote}

Visited our project's admin/sso page. Saw a switch labelled "Enable Atlassian Account" (presently OFF). 

Should I turn that on? If so, when?  

I already cleaned up the project's list of users- saw no duplicate e-mail addresses or names.  I deactivated a few "inactive" users, just to prevent their Jira login from being automatically upgraded to an Atlassian Account and possibly bothering them.  Does that make sense, or is Atlassian going to upgrade all our project's users even if they were deactivated?

[Jobin Kuruvilla [Adaptavist]]

You need to turn that ON when you are ready. Looks like you are ready to go.

Once upgraded, users will start using their Atlassian account password.

[Tony Wallace at Cray]

Thank you- nothing had happened when I checked earlier this morning, so I did turn ON Enable Atlassian Account.