Microsoft has been testing next year's 20H1 update for some time with Insiders in the Fast ring, but there hasn't been a ton of significant changes so far. Earlier today, the company rolled out build 18912, mentioning only a couple of improvements to the Narrator feature, but there may be more improvements that Microsoft hasn't mentioned in its blog post.
First spotted by Twitter user Albacore (via MSPowerUser), there are a couple of smaller changes in build 18912. One of them is that it's now possible to create calendar events directly from the calendar flyout on the taskbar, without the need to go into the Calendar app. Some users have mentioned that the feature has been available before, and it doesn't seem to be available on our test machines, so it could be that the change is only being tested with a subset of Insiders.
Another change spotted by Albacore is in the Windows Update section of the Settings app, specifically in the delivery optimization settings. Currently, users can set a maximum percentage of bandwidth that can be used to download updates in the background and in the foreground, but in the latest build, instead of a percentage, users can choose the maximum bandwidth in absolute Mbps values, so that it stays the same regardless of your total bandwidth.
As with every improvement in 20H1 builds so far, these two are relatively small, but they should make things just a little easier to manage. It's unclear why they've gone unmentioned by Microsoft, but it could simply be that the company is testing whether the changes are well received or not.