It would be strange for these two maps to be suddenly called such generic names as Rhine and Harbor, since all other maps are named after an actual place such as st. mere eglise, Leningrad,... If it would've been placenames, maybe then i would've fallen for it
just as a point of clarification:
st. mere eglise = mp_dawnville.
On the actual Test server (the genuine one) they are indeed testing mp_harbor and mp_rhine. what descriptive name (st. mere eglise is a descriptive name for mp-dawnville) they are giving them is anyones guess.