It's not uncommon for a company to take a look at the equity incentives it's given to employees, in whatever form and realize it's not worth very much and try to make good by giving replacement incentives. I've been at companies where they replaced underwater options at $N a share with at money options at $M with $M being much less than $N (of course the stock continued downward and I left for other reasons before anything vested); for a not yet public company, poorly priced options being replaced with RSUs makes a lot of sense, because the company may not be able to increase its valuation, but it doesn't want to decrease it, and options issued under FMV don't qualify for exciting tax programs.