I think the real greek words translated are really that they may know you. But what motivation could they have to change that back? Earlier the WT org would publish extensive so called interpretations of deep prophecies and such, applying the whole bible to themselves. So they preached that those deep explanations of how giving a talk fulfilled an entire page of revelation prophecy in the bible was 'taking in knowledge'.
Now they've stopped publishing deep interpretations since they have no idea what they mean and don't want them to bite them in the behind. So since every article and teaching now is 95% "obey the GB", "Do service", "Obey the GB", "do service", "trust in the GB", etc, in every possible way to change around words to say the same thing, the sheeple might start thinking they aren't 'taking in new knowledge'. This becomes a problem when they start to study the bible independently to take in the knowledge.
So.....to fit the current practice and doctrines, they saw it would better fit to change it back to the original wording. Now they can say, you don't need to study, etc, you just need to KNOW Jehovah/Jesus and obey the GB.