There are also frequent commits to swift master and projects like swift NIO working on windows compat, from google. Also the S4tf stated they had future plans for swift on android.
The difference is that S4TF is an internal google team. I can't imagine they wouldn't coordinate with the android team, especially given the benefits that easy ML will bring to apps.
It was truncated to one day when they made it virtual. There were swift announcements slated for day 2, which was cancelled entirely.
Regarding windows: https://forums.swift.org/t/new-swift-installer-for-windows/3...
There are also frequent commits to swift master and projects like swift NIO working on windows compat, from google. Also the S4tf stated they had future plans for swift on android.