Times New Roman is a Windows font - the license is bound to the OS, it is not platform neutral.
The decision for a fixed font set in all clients is a decision for notes that look and work alike on all platforms. Asking for OS-specific fonts is of course ok - but is against the philosophy on which v10 was build. To replace TNR, you can use the Serif font.
If you want an omelette, you have to crack some eggs.