Got a weird one here.  It seems someone else on the steam forums has also had this happen, but they haven't received any helpful response yet.  Here's the situation.

Forges of creation shows as installed under the DLC tab insteam

Forges of creation does NOT show as being installed in the DLC  store page.  Clicking the "download" link will launch the game instead of starting the download.

In game, it's as if the content does not exist.  It is impossible to research scythers, the quest for them never pops in game, the only clue to their existence is during games with the allayi.  You also don't see the sisters of mercy hero available in the shop, ever.  Validating the game cache doesn't solve anything.

The weird thing is that in previous games, I've seen them.  So something suddenly caused the content to not exist.