Free respecs are only given when the structure of the skill tree changes, such that if you were to log in and NOT receive a free respec, your character would be broken.
For example, if you used to have 3/3 in a skill box, and we changed that skill so that it now required another skill that you didn't have, or we changed it so that it only had 2 points and you now had 3/2, you'd have a broken character. And that would be bad.
We don't give out free respecs based on an arbitrary judgement call as to how many changes were made; we give them out so your characters will continue to work. Hope that makes sense.
Then explain why Shadows got a re-skill lol. I have a Shadow Tank and the only things that were changed were visual (a tooltip was changed, and 2 animations were changed that have no effect on combat). Don't get me wrong, I'm glad I got another free respec, but I'm not sure why I did!