Yes for ESPP but no for RSUs, which is what folks are talking about here. Selling RSUs when they vest incurs $0 capital gains.
For a stock with lots of appreciation, the real bonus is in the stock price appreciation in the 2 year during which the price is locked in.
That part gets taxed at capital gains if you hold the stock long enough.
https://www.mystockoptions.com/content/how-long-must-i-hold-...