TS – you and benephraim are conflating hachanah with muktzeh.
Muktzeh: area of halacha that deals with –
A) moving items that have no shabbos use, are expensive and liable to be damaged, or are routinely used for forbidden purposes. (Moving an item that has a use for weekday and shabbos and is not used for a forbidden activity, such as a shabbos/yom tov/ weekday siddur, poses no issue, nor does a weekday siddur, because it is not used for a forbidden activity, it is not expensive/liable to be broken, and ot has a purpose – it can be read and studied). The reasons for this prohibition are subject to a machlokes rishonim. Rambam holds it is so that the way we move items should be different on shabbos, the same way our dress, speech, and walking are different, i. shabbosdik.
B) items that were not available/ready to be used at the onset of yomtov are called muktzeh. This is a machlokes tannaim and we pasken like rebbe yehudah hanasi, that there is such a concept on yom tov but not on shabbos. According to rabbah it is deoraysoh. A person is “maktzeh” , puts these items aside in his mind from useage on yom tov.
It could be you are confusing the two issues because rabbah calls his muktzeh “hachanah”, since whatever one uses on yom tov must be “muchan”, prepared and ready to be used at the onset kf bein hashmashos.
That has nothing to do with the prohibition of preparing food, items, or making plans on shabbos for weekday useage/activity.