I always thought
koth would fit TF2 quite nicely as a play style, but reitterating what Nineaxis has already said, Arena makes it a fairly redundant mode to implement.
I find it an interesting "leak" as for starters, although you would think this would go without saying when trying to fake something and make it look legit; stuff like this from the steam forum is usually riddled with retarded spelling mistakes. This how ever, is not. Not that that's a non-flawed reason.
As far as humour and writing style is concerned, it also depends on which developer ended up posting the blog update, and what they want the audience to get from the blog release.
Plus, yea, "free fake email" tab lolwtfwut. Although that is exactly the type of response i would imagine from Robin.
If i were Robin, just for not being able to spell or use simple grammar i would have emailed a virus to that person. Urgh, i know it's the internet but ffs.