I do not think FPP is a major issue, there are several good first person stealth games. Including classics like the first Thief from 1998. But I am also not sure if traditional stealth gameplay will be a major element, since there is apparently no stealth meter of any sort on the HUD (maybe it requires specific cyberware, though). I do not recall if the enemies have any "suspicious" state either, where they did not fully detect the player's character.
Remember, the game is not finished. It's definitely plausible the devs can implement some type of indicator over the enemies' head which signals their awareness to your presence. Hopefully in one of the next gameplay reveals they emphasize a stealthy approach.