In DxoMark DR in A7ii vs A7iii is 13.6 vs 14.7 Evs.If you look at Thom's article and as well as dxomark you will see there is a 1/3 stop improvement in DR at higher ISOs. There is no improvement in noise.
This reminds me of many asking for a BSI sensor thinking it will make a big difference when in fact the impact is less than 1/3 stop improvement in noise. And this noise reduction would only happen with higher pixel densities such as would be found in a 40mp m43 sensor.
As long as it is cost effective then it makes sense to use these advancement but m43 sensors are not somehow hindered if they are not used. It would make more sense for Olympus to invest in computational photography where much greater gains are to be found.
Sports (Low-Light ISO) is 2449 vs 3730 ISO.
Overall score is 90 vs. 96. To me these look like big improvements.