I've always found the one year cliff funny, since investors don't have a cliff.
I've been hoping startups would start doing this for a while, and think DD is really a pioneer here and think this will become a trend. I know personally I turned down a few opportunities at promising startups simply because I was young, in my twenties, and a year felt like a long time. I found the probability of a life changing event that would require me to move and leave a company too high, and didn't want to bust my butt for 10 months with a salary cut, then have to leave and get no equity. So I said "no" to a few opportunities that otherwise would have been great.
Currently incentives first your first year are to focus on not getting fired. Now it can be on making an impact.