I believe they would want to more people to buy Momentum and advertise it as they found it sound great and comfortable as the company advertised their Headphone. Thats why they should be bother about it.
As for the design, I can see it can be made a little bigger on the outside and much bigger on the inside by thinning the earpad a bit.
but by releasing a revised version of earpads, they would be admitting that the original earpads are kind of faulty... most companies aren't down like that. considering the money required to make new earpads w/ little profit margins, i doubt that would be something they wld b interested in.
the momentums are already selling well w/ their current earpads, so i personally think it is very unlikely that sennheiser would release any new earpads. we can all dream tho lol. if they did, i wld def buy a new pair of momentums hahah