That is not really true.I don't think if it is true. You can buy/sell crypto directly on their app.
You can buy something, that is bond to the bitcoin price. But these are not real bitcoins.
You are not able to send them to your private wallet or transfer them out of Revolut.
So, you do not buy or own bitcoins there.
And Revolut is not crypto-friendly at all, if we are talking about real bitcoins.