This is true, however this is simply a custodial bitcoin investment service. With the employee having the ability to sell on demand, self-custody can be as simple as selling back to NYDIG and at the same time buying BTC on an exchange (where withdrawal to self-custody is possible).

Not the greatest approach, but this at least expands exposure to the bitcoin exchange rate to those who might not otherwise participate. And the employees aren't forced to use this, ... they can still do whatever investment on their own outside of this arrangement, just that it doesn't come straight out of their paycheck if they do it themselves.