My interpretation is that each "monorepo" is a big git repository that consists of a collection of individually-deployed services, as opposed to having a single git repository per service.
I do not know whether that's what the blog author meant by that though.
I got that impression too. I can imagine the Pintrest monorepo, for example, has the website and server code together.
Their iOS and Android repos may contain the code for multiple apps. Though, I'm not aware of which other apps Pintrest (the company) creates besides the obvious one.
It sounds to me like you don't have a monorepo at all and instead have six repositories for six project areas.