Er, they submitted the TS to ISO for inclusion in the standard ("The Modules TS is sent out for its comment and approval (PDTS) ballot."). That's the final step from the committee for including it in C++20.
It was submitted for PDTS (proposed draft technical standard), which means it goes out for balloting to ISO national bodies. That balloting either succeeds (at which point you have a Techincal Specification) or it comes back to the committee with comments that the committee then has to respond to (and then another round of balloting happens). Once it's accepted as a Technical Specification, it's still not part of the C++ International Standard. That's a decision the committee comes to at their own pace, much like what happened at this meeting where the Concepts TS was accepted (as amended) into the IS.
Think of a TS somewhat like a beta. There's no assurance that the contents of the TS will go into the IS at all or in the exact form it was originally specified in, but that's certainly the hope when the TS is published.
