WASB page blob support documentation in Features list at the top:
Supports both page blobs (suitable for most use cases, such as MapReduce) and block blobs (suitable for continuous write use cases, such as an HBase write-ahead log).
Which is actually the opposite. Block blobs are better for typical big data use cases, and page blobs were implemented to support the HBase WAL.
It is also mentioned that
"Page blobs can be used for other purposes beyond just HBase log files though."
This is not strong enough because page blob has been tested only in context of HBase write ahead logs. They have not been broadly certified for use across the Hadoop ecosystem, hence is not recommended for use as a general purpose file-system via Hadoop cluster