(...No one asked, but here are my $0.02 ;-)
You need typescript in your environment to use typescript!
The four formats the OP listed can be read by anything from Ada to EXCEL. But typescript can only be ready by a TS build flow.
In fact, I think JSON was a bridge too far. A config file shouldn't need a compiler.[1]
FOR GENERAL PURPOSE: big no.
BUT: If this is purely for TS projects where the tooling already exists, then OK. I'd use it.
EDIT [1] I'm referring to the article's early suggestion to run JSON through JSMin to support comments. So transpiling is more apt, not compiling.