For starters, this isn’t my idea, but one of the pinned ones I remember from the original game suggestions channel and wanted to make sure it gets in.
The game mode is an interesting one: one player out of the team becomes a POW inside the target compound.
The main team would infil and try to rescue the other player, while the other player could decide to try to work inside out.
Maybe you the POW has a shiv and tries to sneak his way out, maybe he can save himself from execution, or can just sit there and wait to watch his guard get smoked.
Either way, the idea of one player being hostage while the rest of the team being the rescue team sounded like a good idea then, and hope it could stay in the original game.