Two days ago, Microsoft released Windows 10 Insider Preview build 18362.10005 to the Slow ring, allowing third-party voice assistants like Amazon Alexa to work over the lock screen. All of the new features were turned off by default though.
Today, the company released build 18362.10006 to the Slow ring, turning on those features. That should be all that's new today, although it's not entirely clear since there's no changelog. There's only a tweet that links to the blog post for build 18362.10005, and the blog post isn't even updated, as it normally is for serviced builds.
Here's the full list of new features, which should be turned on in today's build:
Windows containers require matched host and container version. This restricts customers and limits Windows containers from supporting mixed-version container pod scenarios This update includes 5 fixes to address this and allow the host to run down-level containers on up-level for process (Argon) isolation.
A fix to allow OEMs to reduce the inking latency based on the hardware capabilities of their devices rather than being stuck with latency selected on typical hardware configuration by the OS.
Key-rolling or Key-rotation feature enables secure rolling of Recovery passwords on MDM managed AAD devices upon on demand request from in-tune/MDM tools or upon every time recovery password is used to unlock the BitLocker protected drive. This feature will help prevent accidental recovery password disclosure as part of manual BitLocker drive unlock by users.
A change to enable third-party digital assistants to voice activate above the Lock screen.
Slated to arrive this fall, Windows 10 19H2 will be a pretty minor updated. It's going to arrive in the form of a cumulative update, so you can expect delivery to be much easier and more seamless. It's only being tested in the Slow ring for now, so if you want to test it out, that's where you'll need to be.
Update: The blog post has now been updated and confirms that the only change is that the features above are now activated. It's also worth noting that this build is only available to some Insiders in the Slow ring, so you may not see it on your machine.