Yes, this is true, but there is the possibility that a given service could take back MQA and many have local MQA files that can be still unfolded by wiim app.
Anyway, to be precise, in a different way as Tidal did Las summer for hi-res MQA's, totally replaced by hi-res flac, this turn Tidal didn't replace 44.1KHz 16bit MQA files but simply removed the flag or header, leaving the pcm content untouched. This make sense, because pcm content among 44.1KHz 16bit MQA and 44.1KHz 16bit master they are derived from, is the same.
You can check this with some dac, like the Bluos ones on Nad amps, despite Tidal removed the MQA badge and even WiiM app doesn't recognize them as MQA, Bluos dac still decode those file as MQA, exactly as before.
I'm not sure that makes me happy, since NAD's have some not so frequently little problems with 88.2KHz, the frequency to are unfolded those MQA's...