True. But this is not platform standard. It is just that the SketchUp API has not gone beyond the initial command registration. The Windows C API has functions that can be called to change the text in UI window objects. (Everything is a window or a window sub-class.)
We used to be able to change tooltip text dynamically in the v8 (and prior days) on Windows. This was when the tooltips were a single popup text flag.
Then with the v2013 release, tooltips changed to a definition-like box with an icon, a caption, and a description:
Since then (v2013,) they have been static, and loaded only at startup.
Another thing that loads only at startup, is the names, text and descriptions that appear in the old Preferences > Extensions panel.
Y'all need to keep in mind that the extension settings keys are partly the localized extension name, (with the version string concatenated onto the end,) so each time the user FIRST changes language, it's like they just installed the extension afresh. Each language will be keeping it's own startup settings.
Also, If the toolbar names are also localized, each language will have it's own toolbar location and docking settings. So the toolbar could "seem" to move around weirdly, after the user changes language.
Bottom line, changing language causes registry bloat !
(Now you know why I never released my "LangPicker" utility.
It ends up begging the need for a SketchUp registry cleaner.)