Reads like FUD. From everything I've seen, "Firefox Premium" is not a thing as such. I can't read German, so maybe Chris Beard revealed something different in the interview from what he's been saying in other public meetings - but I doubt it.

There are plans to launch paid subscription services & products in a Firefox brand family. Some of services may even be independent from the browser and be separate standalone apps & products. Some of the services may even - gasp - work in a non-Firefox browser.

Think of things like Firefox Send, Firefox Monitor, Firefox Lockbox, a system-wide VPN, an in-browser secure proxy. Specific plans are still in progress, but I don't think any of them are literally "you pay for browser now"