I got the invite to take the online assessment while studying for recurrent. After that was over, I took the test about two weeks after the initial invite (was given access to the test until June 29th). Hopefully I didn't wait too long to take it. The email stressed the importance of making sure I was prepared before an attempt is made so I did just that.
Somewhat related... I heard that they call prior to inviting candidates in for an interview. Anyone know the area code they typically call from?