I'd argue that any item with lifesteal is not an AD caster item, because they don't spend a whole lot of time auto-attacking to make great use of lifesteal, compared to an AD carry. It's a lot of money to spend when the goal is attack damage, not lifesteal.
That being said, there are two problems here. BT is an AD Carry item that fills a partial role for AD Casters: big-ticket AD item. Sanguine Blade servers as a replacement for the AD Carry item, but removes the effectiveness as a big damage item.
This is where the new Black Cleaver will come in. It's a big AD Caster item.
Right now, on TT, when I play a champion like Pantheon or Kha'Zix - BF Swords are often a last resort. I find my damage doesn't suffer when building Brutalizer, Hex Drinker/Maw, and Last Whisper. I often don't have the opportunity to build glass cannon, stacking BF swords, because I need to survive long enough to take down the bruisers.