But how come ? bitcoin price right now is very dodge and unstable.They could pay them 890$ worth of bitcoin tomorrow it would be 700$ or less. I think it's a bad idea to adop bitcoin as payment method right now , better wait till lightning network is introduced.
And on the other hand, they could pay them $890 then tomorrow it will $1,000. Make sense. That's why it's not mandatory and I think those employees only who are interested are bound for bitcoin payment.
Honestly I don't see any problem if employees there will accept bitcoin as salary as unlike in other country, they have lots of options to used their bitcoin as there are lots of physical shops that accepts bitcoin as payment just like the usage of their usual Yen currency. And no doubt , bitcoin usage there will be more present in the future.