This is where some shill is supposed to crawl out of the woodwork and point out that MQA (as distributed today) doesn't have per-play authorisation and thus won't suddenly stop working in this manner. That is true. However, it is still a proprietary format. Sooner or later, it will be impossible to buy a new DAC with MQA support. If your old DAC breaks, you're screwed. The same goes for software decoders. At some point, the last Audirvana version to support MQA will no longer run on the latest OS releases. Again, your MQA files become unplayable.
If you don't believe this will happen, go to https://samples.libav.org/ and grab a few files at random. See how many will play in Jriver, for instance.