I think the author is just saying not to have draconian testing requirements for every PR like some companies do.

But really, I can see it. Firstly, a lot of engineers suck are writing tests. White box unit tests with interfaces and mocking everywhere tightly couple code blocks together. Integration tests are nice but take a lot of effort to get right while also keeping them performant. When (not if, remember we're talking about an early stage company) the codebase and/or the database schema changes dramatically it will often break the tests which is just another hangup.