this is not a wise move for anyone at this point because of a lot of difficulties that the employees will encounter.
the biggest one is going to be the price volatility. we are not yet at a point where prices are stable so that you can pay people with bitcoin as a currency.
the other one that comes to mind is that cryptocurrencies except bitcoin have no usages as a currency. for example if you get paid in an altcoin then you 100% have to sell it in order to be able to buy something like groceries or pay the bills. and as for bitcoin, it has usages as a currency but they are not that many options. for example you may find a way to buy groceries with bitcoin but you may end up paying higher fees (like using the bitcoin debit cards and paying their fees).
As a salary, cryptocurrency, I think, first of all disagrees with employees, because the price of cryptocurrencies fluctuates, and when prices are good, they may get more, but if it is not good. Second, employees earn wages or want to live. When Bitcoin has not yet become mainstream, they also need to change the cryptocurrency to legal currency, which is even more troublesome for employees. This is not a good idea.