It is a thing for me! I rotate all the time. Things happen, pulled muscles, colds, etc. can dictate changing pillow loft, firmness and support. Having more than one pillow can make a big difference in your comfort and overall sleep quality because different situations often call for different types of support. When you have a stuffy nose or sinus pressure, an extra pillow can elevate your head and help you breathe more easily. On days when you’re dealing with sore muscles, a firmer pillow can offer better neck and shoulder alignment, while a softer one can provide gentle cushioning. Side sleepers, back sleepers, and even those who occasionally sit up in bed to read or relax may each benefit from a different pillow height or firmness. Keeping a small variety on hand allows you to tailor your comfort to how your body feels each night, ensuring more restful and restorative sleep.
I would even add inclined sleep into this category. Not everyone has a bed that allows you sleep on an incline, but there are many health benefits. Here is a short thread on that subject.