Generally, such things are controlled purely by the color management settings. All Lightroom does is follow the directions in the printer profile selected, whether printing or soft proofing. Try selecting different profiles and see if you find one without the blue cast. But yeah, since these profiles are provided by the printer manufacturer, it does seem that Epson is passing the buck.
However, we are aware of some issues in Yosemite (actually introduced in 10.9) that lead to issues with Lightroom being able to read certain color profiles. But this is generally with monitor profiles, doesn't cause color casts, and doesn't effect print (it's actually a Gamma issue). But maybe it is related and Epson is right. If that is the case, Apple is supposed to be fixing it in the next update for Yosemite (fingers crossed).
Try Color Management by the printer.
With my printer - which is not an Epson printer - I get better B&W prints when I select <Managed by printer>.
The tonality range is better, particularly in the highlights.
It might not work that way with your printer but it might be worth trying.