A recent PR in the react-native-localize package (migrating the module to the new architecture) removed Windows support from the module.

See author note on reasoning:
"I removed windows support in react-native-localize v3 as https://github.com/namrog84 (who wrote the PR to adds it - and is the maintainer of this part, as I don't have a windows computer and cannot debug / review this) doesn't work on RN anymore
I already sent a message in this channel, got not response. Can someone work on migrating v2 windows module part to v3? zoontek/react-native-localize#216"

Filing issue to track work to re-add Windows support for this module.