I Was Just Wondering if It Was True That the Higher Your Cheekbones Are the Stronger Your Cheek Muscles Are?

I would say that it is not true that higher cheekbones necessarily have stronger cheek muscles.  Having high cheek bones or strong cheek muscles are independent of one another.    

Thank you for the question.

Cheek bone as a bone made of zygomatic arch and its size is not directly correlated to the the  soft tissues person has.

However, what people call 'cheek bones' on a face corresponds to the  prominence of lateral part of the mid-face. The projection of it depends on how prominent is zygomatic arch is and the amount of soft tissue overlaying it-including muscles, fat, skin etc. So in lay persons term people with more soft tissues even without very prominent zygomatic arch might appear to have more projecting cheeks.

Furthermore, facial expression muscle exercises is considered to help youthful contours of the face and is advocated by some practitioners.

The prominence or height of the cheek bones has nothing to do with the strength of the cheek muscles.