Literally says you need to own MZ to use these.
Viewing post in RPG Maker MZ Tile Collection comments
Weird Kenku is correct. Because these are edits from the RPG Maker MZ RTP, you MUST own MZ in order to use these edits. When MZ first came out, it came with a free copy of MV, so those people can use these in MV. But not everyone purchased that particular package. If you own both, you can use these in either version, but if you do not have a license for MZ, you CANNOT use these.