Better Access Points attenuate WIFI strength based on need (tri-band AP such as the Fritz box 6000) , I doubt that attenuating the signal by 2-3 dB does a lot for sound quality....the ultimate test is switching the thing off in the middle of a track or wrapping it in shielding material.
(not saying the effect of a wooden enclosure is not real, planning to build one)
(not saying the effect of a wooden enclosure is not real, planning to build one)