Office 2021 replaces Office 2019, and it's the ... the support lifecycle a bit. Windows 10 client LTSC is getting five years of support now, although IoT Enterprise LTSC is still getting 10 ...
We can expect that the next LTSC *after* Windows 10 Enterprise LTSC 2021 will be built on Windows 11. And it will also keep the 5 year support. However, that's expected in 3 years or so ...