This is handled by the ELocTextPlatformSplitMode enum, used by FLocTextHelper (default is ELocTextPlatformSplitMode::None to preserve old behavior), and allows you to optionally split localization data for all platforms, or for any NDA restricted platforms. Note: Any localization data that is used by multiple platforms is still considered platform agnostic, even if it appears only within platform specific files.
#jira UE-65600
#rb Francis.Hurteau
#lockdown Matt.Kuhlenschmidt
[CL 4761508 by Jamie Dale in Dev-Editor branch]