«¿Qué es eso de que no vas?» Subordinadas sustantivas dependientes de artículo y demostrativo neutros. Hechos consabidos y reproducción del discurso.

Abstract

In modern Spanish there are some constructions formed
by a neuter demonstrative or article (esto, eso, aquello, lo) followed
by a substantive clause introduced by de que. These constructions
arose in the 16th century as a result of the extension of the pattern noun + de + que + substantive clause, which also began to develop
in this century, besides the medieval pattern noun + que + substantive
clause, and its use was increased in the following centuries, especially
in the 18th century, when they reached an usage rate close
to that of modern Spanish. These constructions are specialized in
making reference to facts and things that are already known, and
become a typical procedure to introduce reported speech fragments
within a larger textual unit.