And I didn't say the protests have anything to do with religion. I said extremists in those countries will take any chance to make a move. Remember the Arab spring? It started as a protests against governments and it didn't end well for some countries.
Now demographics has changed and the role of Islam risen, but it is still very far from being a concern, compared to other Central Asia republics:
"As did its predecessor, the 1995 constitution stipulates that Kazakhstan is a secular state; thus, Kazakhstan is the only Central Asian state whose constitution does not assign a special status to Islam." [2]
Of course, some extremist do exist in Kazakhstan (what country they don't?), but their influence is very minor - this is indeed very secular country and not only in constitution, - and I do not think anything close to Arab spring is possible. My biggest concern is Russian intervention, frankly.
[1] https://en.wikipedia.org/wiki/Demographics_of_Kazakhstan
I don't think anything like the Arab spring is possible there either, but the islamic groups that wander around can do a lot of damage anyway. That was my only thought, I hope they don't manage to do anything.