I was messing around with commands and noticed what I presume to be unintended behavior for the @e[type=] selector. For one thing, the entity tags are only listed as NOT arguments, like @e[type=!#minecraft:arrows]. It does not suggest @e[type=#minecraft:arrows]. Additionally, upon typing a #, whether ! is used or not, entity tags stop being suggested. Like if I type @e[type=!#], after the # is typed it will not suggest tags.

This is unlike other instances where tags are used, such as the /locate and /locatebiome commands which both will continue suggesting tags once you type #, like /locatebiome #minecraft:has_structure/end_city for example.