Offcourse they are just emulators, as they only mimik (emulate) the chips behaviour as seen from the outside. They might get closer to the orginal then UAE, but thats only due to the efford involved not to the method used.
A real reimplementation would be opening the chips and transfering them to the FPGA gate by gate.
A Minimig might have more emotinal value for you, but the underlying principle is still the same as with UAE.
