That’s an old link, and a native 32-bit distribution has no longer been supported in Manjaro for years already ─ 32-bit compatibility for applications is still supported.
Back when the 32-bit Manjaro 18.0.4 image was created, it was already exclusively being put together and maintained by one person among the team ─ @jonathon ─ but that person has in the meantime left the team, and the decision was also made to instead offer an aarch64 version of Manjaro alongside of the x86-64 (amd64) release, and to focus on those two only.