I am guessing that SMSL decided to make at least one model that can process MQA due to Alibaba choosing to use MQA in their Xiami streaming service in China. This way Xiami customers can buy from a known Chinese brand instead of these other odd or extremely expensive (e.g. dCS) brands that support MQA.
Edited to add: it's possible that Alibaba gave them an incentive, or it could just be SMSL thinking it could be useful to get a few extra customers in case that streaming service's numbers improve. At any rate, I'm sure it was a simple enough "feature" to add, since they are probably just using the onboard MQA from the ESS chip. Most of the other recent SMSL DACs have been using AKM, which doesn't have a deal with MQA. Anywho, I guess we'll see if it has any market impact. Doubtful, I suspect, since Tidal is a dud numbers-wise, unless Xiami does a significantly better job of marketing itself to audiophiles and the general listening public.