According to their press release, Yellowfin BI version 5.2 "includes a significant OLAP overhaul, with the introduction of OLAP4j and support for PALO, BW as well as enhanced connectivity for SQL Server 2005+".
Nice to see olap4j gaining wider adoption. Though not too surprising, given connectivity options that it opens up. And bear in mind that because olap4j is open source, for every product that mentions olap4j in a press release, there may be dozens or hundreds of others that are using it and not talking about it publicly.
Increased adoption is good, whether or not vendors choose to announce it. We know if vendors run into issues, they will log them and someone would fix them. It makes olap4j better for everyone.