OcO, all these packs are seriously amazing!
People are asking you about the license, because they want to use the art and they want to know if it's in that category of "open" assets. If you see the free packs as a way to make yourself known, please consider an open source license! This allows everyone the peace of mind that they can use it without legal risks in the future. There are whole websites dedicated to art like this (like opengameart.org).
You can decide to allow commercial (CC-BY) use or not (CC-BY-NC) with those licenses. If you don't, a lot of people (like me) will have to pass because usually at the beginning of a project we want to keep the option of selling the game.
I say all of that because one of your pack says "please don't resell my work", which probably means not to resell the art by itself, but that is not clear and introduces a legal risk.
You have the absolute right to choose your license, and people will follow them (and give credit! it's a requirement of most licenses except CC0). And thanks for the amazing art!