Ja, das meint er.

Folge einfach seinem Link und Du findest das:

After an additional 2 month grace period, those platforms that require
external toolchain integration that aren’t supported by the release
engineer’s release scripts will be removed. This will happen on or about
2020-07-31.

The timeline gives powerpc, mips, mips64, and sparc64 9 months to integrate
either into an in-tree compiler, or to have a proven external toolchain
solution. This is on top of the many-years-long warnings about this being
the end game of the clang integration.