One reason a yoga mat might not work is the width. I have a good, long yoga mat that more than covers the length of wheel-on trainer + road or TT bike, but it is not wide enough to cover the feet of said trainer… and the rounded plastic feet of said trainer were lost about four moves ago, so it’s just exposed metal now… not good for hardwood floors. And cycleops no longer supports the Fluid2, which gives me a great excuse for a Kickr Core or similar! 
I would assume most of these trainer/treadmill mats are plenty wide enough, but it’s worth double checking before spending any coin.