> Is there much space for opposing views on a forum answering science questions?

Perhaps more than anywhere. Science is a process of challenge and response, not a static body of knowledge.

> Presumably the purpose is to answer from established science.

"Established science", which is still subject to debate itself, isn't what link aggregators cover. They bias towarss stuff more like science news and novel study outcomes, which are nothing to do with established science except as a seed for critical discussion.