This speaks for itself:

An Open Letter to the Chiefs of EMC and RSA


Securing Smart Machines: Where We Are, Where We Want to Be, and Challenges

I have confirmed from multiple sources that the session is still on the schedule, and he has not cancelled yet.

Update: Mykko updated his post and he is now pulling out of all talks. He also says:

While I am glad to see that many other speakers have decided to cancel their appearances at RSA 2014 in protest, I don’t want to portray myself as a leader of a boycott. I did what I felt I had to do. Others are making their own decisions.

I’m glad he cleared that up.