I did - I felt like it was important to get ahead of potential emotional meltdowns instead of waiting to see what happened & then doing crisis management. It was also part of my "new normal" which included No More Secrets. Since we were separating, there was no doubt she would at least have some bad days emotionally. I felt like a heads-up to her teachers was fair to them too - how could they know what she was dealing with otherwise?
I'm firmly of the opinion that parents & teachers need to be able to work together through these types of situations in order to provide the kids with the best possible support. We were so blessed to have great teachers & counselors, I figured I owed them my honesty so that they could continue to do their best for DD.
They actually helped me to "see" just how normal our situation was - it was far from the first or worst time they'd been involved in a situation like mine. I think they were very grateful for my transparency - it really showed them that no matter what, DD's welfare was my #1 concern. I made it clear that I would always make myself available to her/them for anything that they thought needed to be addressed as our situation unfolded. Good luck Dad!