New date comparison in Workspace not using correct formula

Hello,

I just realized the formula of Percent Change in the newly release date comparison feature in Workspace is using the following: (New date - Old date) / New date

Shouldn't it be: (New date - Old date) / Old date ?

I reported this as a bug to Client Care but they replied with this is working as designed, however I don't see how it makes sense to report the percent change of a number in terms of the new value when you are comparing the new performance based on the previous performance... The previous date comparison feature from Reports & Analytics uses the correct (New - Old) / Old formula, so why the change in Workspace?