TLDR: MQA isn't lossless, is arguably worse than normal flac, and is seemingly nothing more than a (quite effective) scheme to generate licensing fees. With the frustrating addition that if you are a Tidal user, even if you have no MQA dac, and use the "Hifi" streaming quality setting, MQA encoded/lossy files will still be served to you. And the only way to avoid that being to switch to Qobuz.
If you disagree with this post, or if someone from MQA/Meridian is reading this, it would be excellent if you could provide alternative evidence supporting MQA's claims. If they are true it'd be EXTREMELY simple to demonstrate/prove and so the current lack of any evidence other than marketing claims is concerning.