Does someone know if bi-directional cross-filtering will appear in Power Pivot?

Ashvini Sharma, Olaf Hubel - any news here? And more general question - why DAX for Excel is far behind Power BI Desktop and even SSAS? My guess they use the same engine.

For example, recently introduced TREATAS() for Power BI desktop looks like on hold for Power Pivot.

My question is practical - for more or less complex models i prefer to build them in Excel and only on final stage to shift on Power BI Desktop (or directly publish to Power BI services). Above incompatibilities push me to switch directly on Power BI Desktop, but that's not what i'd like to do. 

Thank you