I also did the test after my interview, I asked what it was for and was told it was because I had not yet finished my degree, I took it, and I am going in November.
There were some who didn't take it even though they don't have degrees, some have been offered a job and some haven't...
Personally, I believe there are traits that show in the personality test that require you to take it...but it could be for any reason!
There is no point worrying about the tests
, easier said than done, I know.
Relax, the hardest part is over.