I'm not entirely sure I see the distinction. Given the vast differences in gameplay between Doom and SRB2, the layout's about the only thing that'd remain intact from a port.
There's also the fact that Aries himself admitted that it was nothing but a filler map. If he's going to submit what's more or less a direct rip from another game just for the sake of submitting, it should be DQ'd.
Of course, this is merely my opinion.