Both 32- and 64-bit requirements have been increased.
Previously, 32-bit Windows had a minimum storage requirement of 16GB, and 64-bit Windows needed 20GB. Both of these were extremely tight, leaving little breathing room for actual software, but technically this was enough space for everything to work. That minimum has now been bumped up: it’s 32GB for both 32- and 64-bit versions of Windows.
Source: Systems with small disks won’t be able to install Windows 10 May 2019 update | Ars Technica
