An obvious problem (and one that was highlighted but seemingly ignored) is that you require a significant amount of reputation on Meta in order to get the ability to down-vote something proposed on Meta - i.e. the proposed licence changes. You can only earn this by gaining reputation on Meta itself, so even if you are a prolific and highly rated contributor to other Stackexchange sites you may well have not been able to down vote the proposal, even if you wanted to.
This is obviously going to skew any voting decision in favour of the upvotes. so the 85% approval rating for the changes may not have been anything like that.
In any case, it appears that many of the upvotes were by people approving the idea that the licence terms needed to be re-evaluated, not they necessarily approved of the licence changes as proposed at the time. In fact, by far, the most heavily upvoted individual comments were very much against the proposed changes.
This is obviously going to skew any voting decision in favour of the upvotes. so the 85% approval rating for the changes may not have been anything like that.
In any case, it appears that many of the upvotes were by people approving the idea that the licence terms needed to be re-evaluated, not they necessarily approved of the licence changes as proposed at the time. In fact, by far, the most heavily upvoted individual comments were very much against the proposed changes.