I feel this would have been made clearer had Bishop not being in cryo with the rest of the crew. In 'Alien', Ash was a plant, and thus nobody knew he was synthetic. In 'Aliens', it's common practice to have a synthetic on board - therefore there was no need for him to be in cryo, except for the whole "we need Ripley to find out over dinner for the sake of the plot and plant negative connotations to the character to cast doubts about him with the audience".
I mean, if we are going to be honest, you don't need a synthetic on the ship full stop, anything that particular ai could do could be integrated into the ships' MUTHUR when it comes to navigation/flight etc. (kind of like in Star Trek - why have a bridge crew when you could literally be like "computer, set a course for the Romulan neutral zone, warp 7, engage" "computer, raise shields", "computer, target phasers on enemy warp core. Fire" when you have technology that can pretty much carry out any command, the crew seems pointless. 😂