We've had this communication from Meridian. [believed to have been issued on 23 December 2015]
MQA Software for Meridian Products
MQA Ltd have now issued full public release specification decoding libraries to their partners, which as you know include Meridian Audio. The Meridian Engineering team is currently working on integrating these libraries into our software for testing in advance of full production release in the New Year.
This new software will supersede the current software in your MQA compatible product and will be required to enable the decode of the official MQA content soon to be publicly released by vendors such as 2L, Hi-Res Audio and TIDAL.
So it does appear that a firmware update will be required before any current 'MQA Compatible' Meridian equipment will actually play MQA material (in MQA mode)
Rick