From ICU-20598, there are indeed still users that need/require prebuilt 32-bit Windows binaries.
We used to provide them, but we currently don't (as I think it was thought that nobody was using them).
We should consider [re]building and providing them, since they are indeed still being used.
Aside: We could likely use the binaries from the CI build bots for this, which would mean that we could take them directly from the build bots, and not need to manually generate them. We’d need to modify the build definition to add a 32-bit Release build (we currently only have a 32-bit Debug build), though this could exist only on the maint/maint-* branches.
Note: We will also need to update the BRS docs as well.