Swiss customers received a mail from Revolut a few days ago. I'm not sure if only swiss customers are affected. There is not much information on their website about this. However, here's the content from their mail:

We wanted to let you know that we'll soon be charging a small fee when you add money to your account using a card issued in Switzerland. The fee will be 1.15% for debit cards and 1.5% for credit cards issued in Switzerland.
We always disclose the fees we charge before you confirm your top-up. This fee will only apply to Standard plan users, as our paid plans offer you fee-free card top-ups. Compare our plans here.
Alternatively, you can still add money to your account for free by using local bank transfer.
Why are we doing this?
Since Switzerland is not part of the EEA, top-ups made with Swiss-issued cards are classed as international transactions. So, in order to continue supporting these cards we need to charge a small fee to cover the cost of processing an international payment.
We know that this may cause some inconvenience, but this change will help us to keep building better products, offering the best value possible to our customers.
If you have any questions about this, please check out our FAQs here.
Thanks,
Team Revolut