Proposed resolution:

In [except.uncaught], paragraph 1, [support.exception], and [uncaught], add "throw()" to uncaught_exception().

In article 3E04@pratique.fr, Valentin Bonnard writes:

uncaught_exception() doesn't have a throw specification.

It is intentional ? Does it means that one should be prepared to handle exceptions thrown from uncaught_exception() ?

uncaught_exception() is called in exception handling contexts where exception safety is very important.