UPDATE I went and built this into my add-in for SSDT, more details https://the.agilesql.club/blog/Ed-Elliott/2015-11-17/Create-Stub-tSQLt-t… and https://the.agilesql.club/Projects/SSDT-Dev-Pack
Generating tSQLt tests from a dacpac I use SSDT and tSQLt in my work and I am always interested in productivity tools to help speed up development and make it more streamlined, if there is something that can help us develop better or faster then we should use it.
I have been a great fan of the DacFx for a while and the sample Dacpac Explorer seems to get quite a lot of visits with one mention from ms devs internally using it as a learning reference!