Didn't the WTS like the 144,000 number in the early days because they were small in number?
When they started to grow beyond that number, they had to come up with some explanation.
It's my understanding that in The Finished Mystery, they taught a 4-class system, 2 heavenly (the 144,000 and all other NT Christians) and 2 earthly (The OT patriarchs / godly kings and all other OT faithful Jews).
Later, they changed it to the 2 class system, 1 heavenly (the 144,000) and every other JW (the great crowd).
How anyone looking at the history of this could believe that they have been guided into truth by the Holy Spirit is beyond me.