I doubt there is anybody who would have a very specific research interest in this, but we can definitely apply logic in answering this question. The best position for overall posture and limiting potential muscle soreness is sleeping without a pillow. Though, this certainly limits the comfort of a pillow. People have chosen comfort of sleep over the best sleeping positions for our bones/muscles. Although I cannot specify a specific date, the mass supply of OTC pain medications such as aspirin certainly give people less worry about sleeping in the “biologically perfect” position.

“Sleeping without pillows will help your back extend, and you will rest in a natural position without any consequences or aches. Using a pillow that is too soft can strain your neck muscles and even decrease the blood flow to your head. If your head tilts downward on a pillow that doesn’t provide adequate support for your head, then your airflow through the respiratory system will be significantly reduced. Because of this, you will most likely wake up the next morning feeling light-headed or even with a headache.” Source: https://www.sleepadvisor.org/sleep-with-or-without-a-pillow/