It kinda looks like a parking lot for visitors. Camels, atv's and the such. Could also be that their having a monster truck demonstration and the mounds are a course. My guess is the photo was taken just before the concession stands were in place.

Any chance this might be areas/ structures where they housed the workers? Thousands were needed for years & years ... kinda makes sense right?

Yes, it's a possibility.

The only way to know is really to check it out. If there were some people there it's definitely possible [certain] to obtain precious artifacts or find glyphs to help us figure out by whom, when, why the pyramids were built.