Microsoft has started preparations for the next windows 10 feature update, which is expected to be released in the first half of this year (between April and may). In the cumulative update kb4598291 released today, Microsoft has started testing the enabling package to update your device to 21h1. This also shows that the update rate of 21h1 is not large, and the important update will move to 21h2 in the second half of this year.