@ecto_ruseff
Hi,
I can say by the end of December 2019
Source 1:
https://techcommunity.microsoft.com/t5/Discussions/Top-feedback-summary-for-October-22/m-p/927511
"Meanwhile, you may notice that the top feedback labeled “Option to set a custom photo as the New Tab Page background photo” has changed from “Planned for October” to just “Planned”. This reflects a bit of a delay internally. We are spending more time iterating on the interaction model and visual design of the New Tab Page and we had to temporarily reassign resources. Nonetheless, we are aware that many of you are eagerly awaiting this feature and we intend to get back to it as soon as possible. We hope to get it into an Edge80 build. We’ll update the status when our plan for this one becomes more firm."
This suggests that Microsoft is aiming for Edge version 80 to be their first stable release.
Edge80 is currently in Canary channel, so in about less than 2 months, it will reach the Stable channel and will be the first version of that channel.
Source 2:
https://techcommunity.microsoft.com/t5/Windows-10/Microsoft-s-Windows-10-20H1-release-will-be-first-...
Windows 10 build 20H1 will RTM in December 2019.
that is the closest and most possible date to integrate stable version of Edge chromium to the Windows 10.
Because the next Windows 10 build will be in June 2020 (Build 20H2) and that's very unlikely that Microsoft is going to wait that much long.
so after considering both of those facts, the conclusion is that the stable version will be first released in December 2019.
You can also read this article about the transition
https://docs.microsoft.com/en-us/DeployEdge/microsoft-edge-sysupdate-windows-updates
