This is an obvious site so I am not surprised to see signs of some investigation. That said, many landowners do these kinds of surveys LONG before anything is planned - the parking lot at George & Front was drilled about 10 years ago but no sign of anything happening there either, yet!
This site is an intensification candidate no doubt.
If it belonged to CentreCourt, they'll probably have applications in by this Autumn, sales start next Spring and shovels in the ground by the end of next year.