This talent on page 215 of the core books mentions rhetorical points, I can’t find any other mention of them or any mechanics linked to them. Anyone provide any clarity for these please?

I think they must have meant momentum points. It seems like a pretty good chunk of momentum points for one action, but if your social objective is to spread a rumor, it makes sense that Whispers of Court would give you a big bump towards accomplishing it. And I'm not sure what else could make sense in this context.

I believe rhetorical points are the GM determined number of momentum points needed to complete a particular objective.