If that stadium's ground rules designates that area as "out of play", yes, you are correct...
I have played amateur baseball for 20+ years and have been a player/manager, so I am very familiar with these rules, and I always told my 1B, 3B, LF & RF what the ground rules are for each park and I also would warn them about the situation that you just brought up if the game was tied in the last inning and we were the visiting team...I would tell them if there was any doubt about catching the ball and then carrying it into the "out of play" area, then let the ball drop and live to see another pitch...
Now I do not know if all 30 major league parks have uniform rules for the camera area being out of play, but for all parks that do, YES, with the scenario you mentioned in the 9th inning for the visiting team, it would be wise to let that ball fall harmlessly into the camera area rather than risk catching it and falling in if there is a guy on 3rd with less than 2 outs in a tie game in the bottom of the ninth...