Russian trolls have pushed the Calexit secession campaign. I wonder if they’re involved in this as well.
As I said, I give you the benefit of the doubt, because you don't post that way, and I don't think you meant to here. It's just an unfortunate phrasing, but I thought I'd mention it.
As to the substance of your statement: Yes, this fits the pattern. But I don't think they care whether they split California or not. Splitting it doesn't change things very much. (Unlike, say, presidential elections. And on that topic, it occurs to me that we got handed an absolutely horrible choice in 2016. Maybe we ought to be looking more closely for interference in the primaries, not just in the general election.)
I think the real goal is to create conflict. This is a nice topic to get everybody all wound up about. I think they'll try to amplify that. Whether or not they're behind the proposal, they'll try to rile up both sides.
One of the things to watch for is the reasons that are presented for people to become agitated. Since agitprop is not "organic" (for want of a better word), the reasons given for becoming outraged seem a bit... off. Foreign, even. You think, "everyone's freaking out about this, but it doesn't quite resonate with me". That's a hint that it may be manufactured outrage, rather than real.
What's the right phrasing? The way you phrased it fit a pattern in my mind. That's not much of a concern if other people don't share that pattern. (Judging by the downvotes, not many do.) To placate me, you might say "just search, and pick a source that you consider reliable" - that eliminates the possibility of some fringe view whose only sources are fringe. But that's me - that works for a sample of one; any further applicability is uncertain.
> Or do I need to source everything?
That might be the answer. Posts are read more than they are written. If you google it, you save 10 or 1000 readers from having to google it. (Of course, if some of your readers consider BBC to be "fringe" or "part of the deep state" or whatever, the link you choose from the search may not satisfy them...)