Do you plan to bring back interrogation similar to the original x-com? I'm hoping to see some interesting ideas around this now that we know there are factions.
Interrogation against faction members (allies and enemies) would be very interesting. Perhaps to unlock faction specific technology, or information on supply depots, movements, breakthroughs or even to turn assets which may act as a sort boost or repair to faction standings.
Later as technology allows for interrogation of the aliens could be a way to fill in backstory, unlock points of interest, speed scientific discovery, etc.
Like original x-com, there could be some form of taking the subjects alive due to non-death injury leading them to be unconscious or weapons that stun or disable.
Would be really awesome to be able to continue interrogation through late to end game even using interrogation against the same type of units. Making it worth while to attempt live captures throughout the campaign.