It looks like, eventually, this will be the way that any type of ‘native’ query (ie a query that you write and give to Power Query, rather than a query that is generated for you) is run against any kind of data source – instead of the situation we have today where different M functions are needed to run queries against different types of data source. I guess at some point the UI will be updated to use this function. I don’t think it’s ‘finished’ yet either, because it doesn’t work on Analysis Services data sources, although it may work with other relational data sources – I haven’t tested it on anything other than SQL Server and SSAS. There’s also a fourth parameter for Value.NativeQuery() that can be used to pass data source specific options, but I have no idea what these could be and I don’t think there are any supported for SQL Server. It will be interesting to see how it develops over the next few releases.
It’s good to know that you can parameterize queries now.