Yes. They are in the process of redesigning it. Luckily I have one from my old m80s that still works great.
Interestingly...when using the 3 button vs the 1 button that came w the M100s...the sound of out of my MacBook Air is significantly quieter. But when I use it with other devices it's about the same. Must be an impedance thing w the output of the Air.
I really think new Macbooks ratchet down their headphone output hard, because my iPhone can push these things with a lower volume setting than the Macbook Pro. It's kinda aggravating.