Did you see the announcement of Microsoft SQL Server on Linux?
Announcing SQL Server on Linux
The good news for us is that we provide support for Microsoft ODBC Driver 11 for SQL Server on Linux x86-64 since SQLAPI 4.1.1. This SQLAPI version has been in MBS Plugins since three years (Xojo Plugins since version 13.2 and FileMaker plugin since at least 5.0)
So when you find your first copy of SQL Server running on Linux, please try our plugin to connect.