The last version in the SCUP catalog is 16.5.2, which was pulled by MS due to a defect.
It was replaced by 16.5.3 on 01/26 but the most recent SCUP catalog still has 16.5.2
Thanks for the heads up, We will fix this ASAP.
"Microsoft SQL Management Studio" has been updated to v16.5.3 in yesterday's catalog update :)