The process is so janky I often wonder if the shop who flushes it gets it right or cares too, and how in the world would you possibly know if the level was correct. Maybe it is a good transmission, but it truly is a horrible thing ram did to owners where they can't even check the fluid level without a 2 video series just to accomplish this. So there is zero chance I would ever trust anyone even the dealer to do this correctly, and eventhough I don't trust them you know for sure you cant trust them if they want less then a grand for this service. So yes I think you should change the fluid but I also suggest you buck up and dyi, maybe get a buddy to help you. Gte the filter and use valvoline maxlife multi vehicle fluid, it is way cheaper and is proven to be equal to mopar unicorn pizz they charge 30 bucks a quart for and also better then high performance fluids which the zf does not prefer. So get the pan and filter and that valvoline multi vehicle and follow the process step and step. Check out motor city mechanic video series on how to.
What is the rational for paying the 1200 to 1500 the dealer wants for this when a new transmission is 4500? It's not that 1200 isnt fair, when you consider what mopar sells that fluid for, the cost of the pan/filter and the labor it costs to do this right, that is in the ballpark of being "fair". If you think you will get all of this for 450 bucks or so, it simply isnt going to happen, nobody worth a spit would do that. It is a quagmire unless you can take on the job, then it is just a challenge. I just posted a dyi on the fords transmsion a similar task, and it was a 3 flashlight job, as in he used up 3 flashlights batteries just to record it for youtube.