Sometime today two fans in the Diablo Immortal Reddit Discord channel confirmed their old closed alpha client briefly updated this popup screen. The servers are still inaccessible, and no login — but this file seems to indicate Diablo Immortal Beta is coming soon.
As per the August 3 blog: “We’re preparing for another upcoming limited test later this year.” That means 2021. There are only 10 weeks remaining in 2021. Less than 70 days. Any of those days can be the start of Beta testing. Hopefully, much sooner than later.