I was 100% certain we had not seen the last of him. After this interview I am now 110% sure since he said we left that door open on purpose.
That said, I am still severely disappointed with Foundry in general. I mean, sure, throwing Revan in there is pretty cool, but it was very poorly done IMO. He didn't seem powerful enough. They could have made him seem more powerful while still leaving the encounter easy. There could have been some lore/story explaining why his power was weakened. Better yet, increase the heck outta his health and then have him run away at like 50% after using some ability that drop everyone to 1 HP and stuns you while he makes some quick I'll be back speech. These are probably fairly poor ideas, I am not a writer, but IMO they should have done something to make him appear way more powerful, cause he's Revan.