The boss fight looked quite Soulsy - the long range gunfire reminded me of Virtua On, that's my frame of reference, I'm not a mech fan and haven't played any AC games. The player character in a white mech went in close to the bigger robot boss and fought with like an energy or laser sword, this looked Souls-style.
The field gameplay, the player in the same white mech seemed to be following a couple of other players in the distance (co-op?) and they were walking (flying close to the ground maybe) through a snowy area towards either a large wall or gate, this seemed Soulsy too, the vastness of the architecture, but it wasn't a castle more like a worn down metal/stone wall or gate. It was quite short.
The survey listed a choice of titles for the game, so I guess that hasn't been decided on yet. Most of them were Armoured Core: [Something] including just "Armoured Core" and both AC: 6, AC: VI, and other subtitles I can't remember, some of the choices didn't include AC in the name at all.