That's a known "issue" and was commented in some other thread I just can't currently locate.
WiFi should rather be reading as non-Cellular 
Anything that is not cellular is currently treated as WiFi - after all, for the WAN side it's irrespective wheter you hopped onto the wire bound network via a WiFi AP which is Ethernet connected to the internet or just cut out that intermediate transport.
Update:
Found the thread