The “pattern” has been true if you look at Sept and Oct only. If it continued, then Shoremen would be November. So can we really see a pattern? Sure, if you call two elements a pattern. But it was already pushing it a bit to call that a pattern in the first place.
Om Facebook they’re hinting a second October update with Anvil and a few skins included (3 heroes in a month, gosh). So probably or maybe KLG won’t be the next featured faction after all since it’s still October when the new KLG hero arrives.