It wouldn't be very difficult to explain a literal maximum of 144,000 away, IMO.
Jesus claimed he had a little flock, and every shepherd with only a little flock would know the exact number. (Jesus hand picked apostles and first century Christians?)
Then he said he had "other sheep" and there would be one flock one shepherd. (Modern Christians who claim to be anointed?)
Then there is a "great crowd" which no man is able to number. (Everyone else?
I seem to remember that this follows what Russel and early 20th century Bible Students believed. Of course Boozerford couldn't stand being in Russell's shadow. Recall the flip flop about "superior authorities"? The WT could flip flop on the 144,000 just as easily. Every single number in Revelation is claimed to by figurative, except 144,00 which suddenly becomes literal.