"This field is required" for RichText field not translated

Steps to reproduce:

1. Create a Content Type with a required RichText field
2. Use PlatformUI in language where "This field is required" is translated for others field types (like French for instance)
3. Create a Content of this type
4. Do not fill the RichText field
5. Try to publish

"This field is required" is not translated (nor translatable using Crowdin in-context)