[Symmetry]

I'd be very surprised is they didn't too. But Spectre isn't just about what's in cache, you have to load secret data and then do another load with a location based on that secret data before the the mis-predicted branch is caught. The number of clock cycles from branch prediction to branch resolution on the Mill is just too short for you to do all of that, just like it is on most in order architectures. Just loading the secret data into cache isn't enough to be a problem. You already knew its address if the attack is going to work.