Question about FIPS Deployment for WebHD

My organization is currently looking to update our WebHD. We are currently at version 12.6 and will be updating to 12.7.5. One question I had for this upgrade is the following: If we update to the most recent version straight from 12.6, would we have to revert back to 12.7.2 in order to enable FIPS if we decide later that we want this feature? I notice that the update path for adding FIPS is 12.7.2 to 12.7.5, so I'm also wondering why specifically 12.7.2 must be updated to, as I didn't see any mention of FIPS in the release notes, although I may have missed it.