As was stated in the earnings call for Q1: "We're on track for R2 to progress to open beta in Q2 and then be generally available in the second half of 2022."
Great to see some progress. But the fact that it is only announced in an earnings call - where you kind of have to answer such questions - makes me sceptical. There is probably a reason why there is no mention of R2 anywhere on the Cloudflare site or other channels targeted towards developers?
So, very soon now.