Looking at the publish profile in my SSDT database project I see an option for RegisterDataTierApplication. It's not clear to me if this is a requirement in order for DACPAC deployment to work.
It's not required to publish a database project. It's more for when you have managed versions. I haven't used it for any of my normal database projects.
MS doesn't have a lot to say on their main page, but here's their short blurb: https://learn.microsoft.com/en-us/sql/ssdt/extract-publish-and-register-dacpac-files?view=sql-server-2017