I just examined my Feb 22 Freemont Model 3P.
I don't see a gap in that area. If there is any gaps, quite small.
There is dust that stops at the seal, so I think the seal might be working.
I've read this entire thread and some are saying their seals are loose in places.
A good rubber weather strip adhesive should cure this.
I'll try to do more detailed examination with more time.
I just took my longest trip in the car. About 12 hours each way, including stops.
The car is generally noisy. There is air and road noise intrusions all around the car.
I'm planning to add weatherstripping and inspect and seal any that have come loose.
The major problems I've been trying to solve is the seal between the window and the body. I think it is a bad design. The window is curved and doesn't fully flatten when closed. The rubber seal is unable to maintain even pressure all around. Temperature and other factors can make it better or worse. That seal is also just pressed fitted with no glue at all and frequently comes loose. I've had it serviced and they replaced both entire door / window seals. They were not installed correctly and even when install it correctly There are still gaps. I measure the gaps with a business card or other similar thin object or paper.
It's difficult to see your picture but it kind of appears the rubber glue isn't holding it into position.
Do you see any visible evidence the dust has gone past that seal?
Have you tried to slip paper? But in any case, if it's obviously loose, then it should be fixed.