It was a big no-no in my old congregation. I knew two friends who were brothers (not only baptised JWs but also siblings). One usually wore a neat, trimmed goatee that suited him. His younger brother was often clean-shaven but grew a goatee several times. On one occasion, he was given a good talking-to by an elder in the back room. Absolutely ridiculous!
It sounds ridiculous me saying it, but sideburns were also monitored. They had to be neatly trimmed (not bushy) and were not allowed lower than the earlobe. I remember my dad 'counselling' me for growing my sideburns down to the point of my jaw.
How's that for control-freakery?