Will the houses be private or help-to-buy etc?

Does it go around the back of Tandle hills?

It appears to corners Tandle Hills in from 2 sides as you can see from this image. It comes very close to the monument

Why do 2 different maps show different areas affected?

Why does this map show Tandle Hills being affected by the development but this map does not include Tandle Hills in the development?
Answer submitted here and reads…
“The second map contains owner-submitted sites for potential development. The owners on the east side of the A627(M) presumably didn't submit their sites.
The first map is the current spatial framework, and the land on the east side has been included in a parcel called the Northern Gateway (see here). That land and the 'missing' bit over the border in Oldham (which includes TH park itself) is green belt parcel OH13.
You can find the green belt survey for that parcel in the PDF linked from here The document consistently rates it in the various assessments as Strong meaning it's most worthy of protection."