In the late '80s - mid 2000s it was "a conscience matter." But we all know what that means: anyone that went to college was viewed with suspicion.
I was actually serving as an elder when the WTBTS sent a letter out changing the policy. I'm pretty sure this was the summer of 2006 or early fall of that year, I'm not sure what month. But the letter stated that anyone that pursued higher education (HE) would not qualify for "privileges." If an "appointed man's" children pursed HE, his "qualifications" would be called into question.
I distinctly remember the letter because I had been attending university at the time on the downlow and felt very upset because of this policy change with no justification and explanation. I also felt upset because now something that had been "a conscience matter" was now to be viewed as being disloyal to Jehovah. I had just finished my degree a month or so before the letter was received by and read among the elder body.
I remember thinking: If this letter had come just a couple of months earlier, I would have been faced with the decision of abandoning my degree weeks before graduating or resigning as an elder.