SSAS 2017 introduces the 1400 compatibility level. Here are just some highlights of the new features:
New infrastructure for data connectivity and ingestion into tabular models with support for TOM APIs and TMSL scripting. This enables support for a range of additional data sources, and data transformation and mashup capabilities.
Support for BI tools such as Microsoft Excel enables drill-down to detailed data from an aggregated report. For example, when end-users view total sales for a region and month, they can view the associated order details.
Object-level security to secure table and column names in addition to the data within them.
Enhanced support for ragged hierarchies such as organizational charts and chart of accounts.
Various other improvements for performance, monitoring, and consistency with the Power BI modeling experience.
There’s plenty more where that came from (unless you’re a Multidimensional fan…), so click through for the details.