This scale is on a different dimension than that of the choice of Go!
Go doesn't impose any restrictions on your efforts of playing nice with a search engine. But it requires the programmer to put some effort into doing so. So far I know, the HTTP server in Go is quite standard-abiding, so there's nothing limiting you there.
Now, if you ask the same question about a specific CMS framework written in Go, the question is more aligned, and is easier to quantify. But that will require you to have a specific framework in mind. The Go language itself provides the tools, not the solution.