Yes, it's this line that gives the hint that the author means Typescript when they mention they will "often times push back on changes that add more complexity

Yes, it's this line that gives the hint that the author means Typescript when they mention they will "often times push back on changes that add more complexity in the type system". They're referring to code that tries to make the type system do too much in the name of "type safety" and end up with overly-complex code. You simply can't get that kind of complexity with a dumb type system like Go's. They still love Typescript, but they don't abuse the type system.