[Question] New Feature support for old projects

In VB the compiler defaults to features from last major version, currently 15 and if you want to use features of 15.3 or 15.5 you have to specify the version specifically in the project file. When VB 16 come out anyone who didn't specify a specific version automatically gets VB 16 features, including features of 15.3 and 15.5. What happens if they had manually set the language version to 15.3 or 15.5 are those setting deleted, do VB 16 features not work, are they prompted to edit the files or something else?