Microsoft has raised the minimum storage requirement for Windows 10 version 1903 to 32GB for both 32-bit and 64-bit Windows.
The minimum is up from the entirely unrealistic previous minimum storage capacities of 16GB for 32-bit Windows 10 and 20GB for 64-bit.
While many people do opt for devices with larger storage than this, the previous minimum requirement did allow hardware makers to produce low-end laptops with 32GB eMMC storage, which leaves users with insufficient space to install new Windows 10 feature updates.
The new storage minimum appears in Microsoft’s recently updated minimum hardware requirements page and comes as the company continues a final phase of Preview testing for Windows 10 1903 with Windows Insiders. Windows 1903 should be released in May and is called the Windows 10 May 2019 Update.
The company also recently updated its minimum processor requirements for Windows 1903. However, these remain unchanged from Windows 1809.
https://www.zdnet.com/article/windows-10-pc-with-under-32gb-storage-no-1903-update-for-you-says-microsoft/