What OP is referring to is the TransferWise Borderless account, which was introduced from last year I think.

From what I remember, you do not necessarily need to have a bank account prior to opening an account with them.
However, note that proof of identity and proof of address are both mandatory in order to join.

In addition to the borderless accounts, TransferWise has made its own debit/prepaid card which you can use everywhere Mastercard is accepted.