You think that Armstrong and company leaked blatant lies which could upset their best trading partner? Driving away the frontrunner doesn't sound like a good way to drive up the price. There's usually a kernel of truth to rumors. The kernel of truth in this one could be that Armstrong asked for Clarke, Blake said something like "For Clarke, we'd have to also get Vejmelka and 50% retention on Chychrun" and the two then went back and forth on such a hypothetical trade. That's not "offering" him, but it's also not taking him off of the table. Blake wouldn't be doing his job if he didn't at least see what his assets are worth. Every player has a price and no one is "untouchable." Long-time Kings fans understand that.
Also, I wouldn't say that the Kings are tight lipped. We often know which players they like, when they're involved in trade talks and, sometimes, even what they involve(d) (ex. Vilardi for Chychrun last year). Some trades (like Fiala) do come as a surprise, but every team has a few of those. Not every team is mentioned in rumors as much as LA and those can't all leak from elsewhere.