This is definitely a thing, there are some albums where the "Master" version has very noticeably better dynamic range and sounds less compressed. But this is the source master, not the encoding. Try listening to the Master version but with the streaming quality set to "High" (which limits it to 44.1/16), the albums which have this for me they still sound like they have better dynamic range with the streaming quality stepped down. My understanding is you still get access to all the "Master" library with Tidal if you have the HiFi sub, you just get these in 44.1/16 quality. If it's a higher quality master though you will still get that better dynamic range.
You can sometimes dig around with the credits and the year of the copyright or the record label to get an indication of what version it is, and when I've compared to other streaming services, even lossy ones like Spotify or Apple music, I can hear the volume / dynamic range differences in the versions they have too and they match up with the copyright year indicated on Tidal. So it's the source master here making the difference, not MQA or HiRes.