At this point, you still have to apply Enable Data Retention to all forms, but you can exclude some forms by tagging them with "skipdataretention."
I wish it were the other way around, though, where we could select only certain forms to have data zapped.
Using the tagging method to exclude forms also doesn't feel very safe, because they're easy to delete. (Seriously. You only have to press 'x' to delete a tag/label. There's no, "Are you sure you want to delete this tag?" check in the process).
@yuniar , any potential for this feature's options to be expanded in the near future?