It is said by Microsoft that the Windows 10 21H1 update will use the build number 19043.Microsoft has been pretty quiet about what’s happening in the next feature update, Windows 10 21H1.
Windows 10X has reached the RTM stage and will be available by the spring release. Additionally, due to the timing of Windows 10X, Microsoft is known to be moving away from tradition with Windows 10 updates, and the next major update will arrive in the fall rather than spring. The uncertainty is whether a spring update will come. There is no statement from Microsoft about the issue, and the Windows Insider team does not comment.
Regarding this, KB4598291 points to a 19043 build. It is stated that this means several things. The first means that the 21H1 process is still going on and will also come via an activation package as we saw in the 1909 and 20H2 versions. Also, it seems that Microsoft once again hits the build number by one number. Finally, 21H1 will receive the same batch updates as Windows 10 version 2004 and 20H2.
It is not clear for now what the new features to be introduced will be. Since Microsoft has not announced this update yet, we just have to wait and see.