Interesting article, but I don't think that the Central banks will give up their monopoly on money, Central banks will in 30 years probably hold bitcoins just as they hold gold. But I don't think that we will see the government paying salaries to their workers in bitcoins.
Private banks that hold bitcoins will probably have a better credit rating than banks that don't have any bitcoins. If banks one day going to lend out cryptos it will most likely be crypto from a blockchain they control. This way we cut end up going back to the old time where every bank was issuing their own currency.
Well, somewhere in the future cryptocurrency can be an alternative to money, but it will never replace money as we know banks they will not give up their power in controlling the flow of money, not to mention the government using cryptocurrency as the main currency. What's written in the article could be a great thing to happen, but looking at how things are right now, this is less likely to happen in the future. However, we don't actually hold the future, and we can't tell what might happen to crypto in the future.