I had noted that the release was scheduled for October 2023.
John Reid has just put online a 23 pages document entitled The new features of Fortran 202x (March 21, 2022):
Abstract
The aim of this paper is to summarize the new features of the revision of Fortran 2018
that is planned for publication in 2023. It is known informally as Fortran 202x. We take as
our starting point Fortran 2018 (ISO/IEC 2018) and its corrigendum (ISO/IEC 2021).
For an informal description of Fortran 2018, see Metcalf, Reid and Cohen (2018).
NB This article is not an official document and has not been approved by WG5 or PL22.3 (formerly J3).