I've been doing a bit of research on this, and all I can say is who knows. I bought a pair a couple days ago, box is clearly labeled simply as Momentum In-Ear but the QR authenticity page says they're Momentum 2 In-Ear. Even the official Sennheiser page doesn't seem to make a distinction between a 1.0 and a 2.0 version, as clicking on "product information" leads me to the regular Sennheiser In-Ear page.
This thread was started in 2014, a year before the 2.0 series was announced, so I'm guessing there's 2 versions floating around, the 1.0 and the 2.0, but both share the exact same packaging and accessories, but maybe some internal changes or else they wouldn't bother changing the "internal" product name that is not displayed in the box. There's a review on Amazon updated on August this year that claims apparently there's 2 types of cable on these headphones. His first pair failed after a couple months, got a replacement pair from Sennheiser but this time around, according to him, the cable was different and it definitely felt sturdier. It's Amazon reviews, so I would take it with a grain of salt.
Would be nice to hear something from an official source, or have a person with an earlier batch scan the QR code and see what the authenticity page says about the model.