Does proton increase subscription rate of existing customers?

As of my last update in October 2023, there hasn't been specific information indicating that Proton (the company behind ProtonMail, Proton VPN, etc.) has increased subscription rates for existing customers. Price changes in subscription services can vary based on company policies, market conditions, and other factors. For the most accurate and up-to-date information regarding subscription rates and any changes, I recommend checking Proton's official website or their communications directly.