SCOTUS hasn't yet ruled on Google LLC v. Oracle America Inc. One imagines that if Oracle prevails in some demonstrative manner they may very well believe their flavor of SQL is a software interface protected by copywrite.
So will all the other 'software interface' owners of the world.
Amazon acquiring EDB and rolling some of the currently-proprietary bits like the Oracle compatibility layer into open source Postgres while increasing resources to developing them could be an interesting play.