According to a report from Eurogamer, Sony has begun telling PlayStation 4 developers to prepare for the launch of the PlayStation 5 in a big new way. Starting on July 13th, games submitted for certification on PlayStation 4 must be compatible with PlayStation 5.
This news comes by way of developer documentation apparently posted on PlayStation's internal partner website, that Eurogamer got its hands on. Apparently developers are able to use their PS4 devkits to perform this check, thanks to an update released in April.
The documentation also apparently states that "compatibility" means that the submission code runs without issues on the PlayStation 5, and provides the same features on PS5 as PS4.
Developers who submit for certification before July 13th are apparently "strongly recommended" to prepare PS5 compatibility as well.