Could be the result of using a better master or the MQA process or both.
Sure! The question that needs to be asked is, if the std file is a perfect copy of the master, and the MQA version "really" does sound different, what does that tell you. It's been shown that MQA is a lossy process and all the rest. To me it's a easy 2+2=4 answer, if MQA does sound different, it is wrong and not what the artist & engineer heard at the console and not what they intended you to hear..
Simply a money making scam to lighten the wallets of the audiophool, just more snake-oil.