Funny, I read it differently. They talk about frameworks, libraries, and best practices.
Effectively, they're talking about standardization across your teams/services so they don't fuck things up. Essentially, you're taking away some of the purported freedoms of microservices (complete independence - eg I can write this service in brainfuck if I want!) and reigning it in a bit so you don't build a pile of trash.
I think of that kind of standardization kind of like deleting code. Stuff like, "We are deprecating support for Python in SRE, no new projects may be shipped in Python."
Anecdatum time: a friend once worked at a company that had separate teams building small services in a small variety of common languages (mostly python and golang). One individual decided that a particular new service that was going to be really critical just had to be written in erlang, and went ahead and did it.
Fast forward to a few years later, when my friend started there. The erlang dev was long gone, and nobody knew erlang or OTP or anything about the service well enough to take ownership of it. My friend was constantly awoken during his on-call weeks because the damned thing kept repeatedly tipping itself over now that the company had grown. He couldn't maintain it other than restarting and praying, and couldn't rewrite it- the company had bigger priorities.
That was the shortest lived job of his career so far.
Effectively, they're talking about standardization across your teams/services so they don't fuck things up. Essentially, you're taking away some of the purported freedoms of microservices (complete independence - eg I can write this service in brainfuck if I want!) and reigning it in a bit so you don't build a pile of trash.