They arent going to swap the bumper.
Paint match isn't an issue of fade either. You have one paint code, but multiple variations of the same color from teh factory depending when they sprayed the car, so matching paint is almost never perfect. Plus, besides the mix of the paint you have other factors that affect the color. The material it is sprayed on, the thickness, the brand of paint used, even the angle that the paint is sprayed at all can affect the color. When you're dealing with 3 stage and 4 stage colors you can pretty much guarantee it will never match, because A) its pure luck getting that stuff to match and B) no one wants to spend the money on how much time it takes to match it. C) the flip from different angles is impossible to duplicate.
Example: The top shop in Edmonton couldn't match a 4 stage color on a LP640, and nothing on them, cuz that is pretty much impossible to do, but the customer was not happy and wanted to take it to us. I worked at the 3rd best shop in town at that time and we used exactly the same paint as the shop he just had it sprayed at, but we thought we'd give it a go with help from the paint rep. Well, we matched it bang on eventually, but after multiple attempts spraying it, and a full day of screwing with mixing the color. Even after all that screwing with it and multiple attempts, matching it was still a lot of luck. Now the only reason we went through all that trouble was because that car was worth a fair bit, and probably because the owner wanted to see if we could outdo the other shop. I can guarantee you no one is going to go through that same trouble for a $50000 car unless there is something out of the ordinary wrong with the paint match.
As for stuff not matching from the factory. Well, my wife's tristage lexus matches perfect from the factory. So does my BMW. So did my last bmw. It depends on the manufacturer. Now i'll agree most manufacturers will not have their bumpers match the rest of the body, or plastic trim, but some do infact match. Infiniti's generally do match pretty good from the factory.
Also, nothing is more durable than factory paint IMO, especially if you're driving a german luxury car. At my last shop we were spraying the best standox had to offer (mercedes required us to use that), which is a stupidly expensive brand to spray to begin with, but has some neat tech in their clear that activates in the bake cycle to harden up more than normal. Yet it still doesn't duplicate what the manufacturer can achieve for durability because they can bake their paint to far higher temps, because they get to spray cars before they are assembled. I'd prefer a shop not touch painting the bumper at all if it was my car.
Now what is likely to happen here with infiniti is they'll take it to whatever shop does bodywork for them on the cheap and get them to spot repair the bumper. What this means is they're going to stop painting at a body line. This is normally a shit way to fix a car, but in this case its probably the least invasive method of repairing it and what i'd want done myself if its on the very bottom of the bumper. I would not want them to spray the entire bumper personally as it is almost guaranteed to not match since you bought pearl white.
Actually, honestly, I'd tell them fuck it as far as fixing the damage, and i'd leave that 3m/xpel over top of 'the damage that you can't see unless you are bending down'. It's Alberta. film or no film your car is going to get raped if you winter drive it. You should see my 335i after just one winter
(Fuck you Edmonton sanding trucks dumping gravel/boulders/razor blades on the roads instead of sand). with our awesomely engineered parking lots you're probably going to drive in to a way too high cement chunk of shit at some point anyway and fuck that lower bumper...
If you really want it fixed though, perhaps tell them you'd like it taken to a shop you use at work and take it to JYC. If the entire bumper has to be sprayed at least taking it there you know you have a good chance of it matching, and if JYC says you can spot repair the bottom, you know its a legit repair to do.