Basically, yeah... They also like to curtail the things that are mistakes too, and remind people that when you hear mistaken reports/rumors from sites out there, you shouldn't hold it against them and remember that sources online get information second-hand... They've expressed in the past how rumors do, to an extent, spiral out of control.
Add to it then that some sites I believe put out "rumors" that are basically fanboy wishlists anyone could come up with and still get some right and some wrong, and you've got a whole dynamic to the rumor-reporting thing that really can get people's hopes up and then let some people down... Not everything over time has come from really concrete sources and some has been more off the mark than on despite being claimed to be "valid"... It happens. Hasbro's reminding people that, till it's out of their lips, it's just gossip and may not come to fruition.
Certain things though, like the AT-TE, have been public knowledge pretty much... The UBP's were the similar in that we'd seen 'em, we'd seen DPCI's, and we knew they were on the way, but Hasbro wouldn't comment. Seems more like the policy is just an across-the-board one even when we've seen an item they haven't personally confirmed yet is all.