When they say they have no money, it doesn't necessarily mean that they're out of funds. It's just that some or most of the funds they have are in digital. What it means is they have no enough physical cash. That's why most of the time, big accounts who wants to withdraw huge amount of money, they inform banks beforehand so when they come to that branch, they're ready.
I think you have an idea of what this is even though government could be selfish not to do the real thing. When they say no money like I said also to what idea you have dropped, they could be having a different financial policy at that point in time but it will not be made public to every body, only to few top officials of the government. Also, the government may be discouraging cash flowing physically but encouraging online transaction as a global practice and also the use of CBDC which is a digital financial policy also.