That's the incorrect belief that causes so many people to hold their RSUs. The day you vest the RSU is the day someone decided to:

   (1) give you the amount in cash (as regular income) 
   (2) take that cash and buy that stock on your behalf
   (3) turn around and give you the stock

and somehow you decide to let (2) and (3) happen without returning to the cash position in (1) and buying whatever else you would prefer to hold. The LTCG clock starts on that day, and all you're doing by holding your vested RSU is let someone else decide to buy stuff on your behalf and make the decision for you.

(that's assuming that there's an ability to liquidate the RSU on the vest date)