Date with no hierarchy with SSAS tabular live connection
At the moment you do not support the bult-in date hierarchy when connecting to SSAS tabular or when using Direct Queries. That is fine as you built this hierarchy yourself in the tabular model (date, month, quarter, year, month + year etc.). However when connecting to your model, Power BI DOES NOT recognize the date hierarchy as a continuous variable (in stead as categorical variable). This means that a) you cannot apply trendlines under "Analytics pane" and b) more importantly when the system interpret the time as a categorical - it will always show a very annoying scroll bar (which it will not when continuous). Even EXCEL can always handle this - even when it is not recognize the data as dates. Put simply:
You cannot analyze time series data at all when using direct queries or connecting to a tabular live connection.