It's been on that page since 2001. However, a more recently published article states "Note: We plan to support .dev and .app by mid-July 2023".

https://blog.cloudflare.com/a-step-by-step-guide-to-transfer...

However, it's now mid-July 2023 and still says unsupported on my dashboard.

I think it's been listed as coming soon for a lot more than a month. We'll see if it ever arrives.