[thxbb12]

It is highly unlikely that the Sony MTFs are reflecting the corrected results.

Why?

Because correction means that the corners need to stretch out a lot, losing resolution as a result.  MTFs like these simulate what the optics do, not what is done to images captured by the lens afterwards.

I know what software distortion correction does to an image thank you.
Are you sure about this statement "MTFs like these simulate what the optics do"?
I'd assume these computer generated MTFs do include the distortion correction that happens in software as one can compute the resolution decrease due to the software interpolation required for distortion correction.
That seems very silly to present MTFs charts before distortion correction as it is embedded in the lens' firmware. Hardly anyone will use this lens without barrel distortion.

Also, by looking at the lenstip samples, it does seem sharp, even in the corners.