UPDATE 11/12: KB4524570 CU Windows 10 v1903 build 18362.476 & v1909 build 18363.476
UPDATE 10/23:
Today, we have released an updated Cumulative Update KB4522355 version which applies to both 19H1 and 19H2.
(v1903) Windows Insiders in...
UPDATE 10/21: Getting the Windows 10 November 2019 Update Ready for Release
Source: Testing the throttled delivery approach for 19H2 | Windows Experience Blog
Direct download links for KB4517389 MSU file from Microsoft Update Catalog:
UPDATE 10/3: KB4524147 Windows 10 Build 18362.388 19H1 and 18363.388 19H2 - Oct. 3
Source: Testing the throttled delivery approach for 19H2 | Windows Experience Blog
See also: New KB4520390 Servicing Stack Update for Windows 10 RP...