I'm curious how these 2 rules interact with each other.

Remote: You are not an Imperial figure for mission rules.

Mission Rule: At the start of each Status Phase, each Imperial figure on the southernmost exterior section suffers 2[damage]... then each of those figure are pushed to the nearest space on the next section... Return the southernmost section to the game box.

So if 88-Z was on the southernmost section of the map when it gets removed, does the companion figure just get removed from the map and then have to exhaust Active Surveillance to Redeploy?

As written yes. Remote is foremost to ignore 88-Z when a mission win condition is to defeat all imperial figures. You have to take the good with the bad, or make sure it's never in the southernmost section.

Hmm, I actually think that's beneficial to 88-Z, since it can just redeploy at full health in the new south section for free during that status phase. If it took the 2 damage, it would be more susceptible to being killed by a Cleave or Blast on the next turn before it could activate. Good to know, I'm considering Reactive Defenses for our upcoming Lothal campaign.