This platform has been developed by VW over a decade ago. It is not something which Skoda has developed on their own, it is Skoda getting to do legacy support for one small part of a large platform family.

"...the Czech manufacturer's development of the specialised MQB-A0-IN"

Not developing as in starting from zero, but developing as in taking an existing platform and modifying/improving it for a new series of cars (in this case simplifying the platform to make it cheaper to produce, and targeting the very lowest end of the car market). Admittedly not a platform we're likely to see in 'the west', and sure it's nothing fancy, but I guess you have to start somewhere.

edit: reading back through the original thread, I agree that you are correct that Skoda is not developing a ground up platform that will be the basis for several VAG cars.

Which is completely different from developing your own platform.

And it definitely isn't something which VW uses to base their own cars on.