There's an OTA update system on the MG4, but it has never done anything. I wouldn't be too hopeful about the MGS6. I expect it needs a shift to a new software architecture, such as the IM cars have done - although the presence of workibg OTA with the IMs has yet to be confirmed.
Hopefully MG will adopt the same / a similar system.
I would also add: if the software arrives in a more mature state, without obvious bugs, then how it can be updated is much less important / relevant.
Many people just want software that works, they are not so bothered about new feature upgrades that arrive later.