I don’t know how you drive, but 50k is pretty low miles for control arm bushings. Also, these days, most people would replace the entire control arm, and that said, OEM BMW parts are pricey, so maybe he’s trying to save on parts and just replace the bushings. When replacing the entire control arm, you would also get new ball joints pre installed. Maybe ask the questions, but don’t take my word on it. My BMW mechanicing experience ended sometime in the 1990,s

What manufacture warranty do you have if its only 50,000, you might still be in warranty, its from the date of purchase.

Some bmws have oil filled control arm bushings. Once they leak out like this, (see the black goop) the control arm will have more movement over bumps and corners and your car won’t handle as well as it did before. It may even cause your car to pull to one side and or cause uneven tire wear.

I would plan to get it replaced sooner than later, but you’ll be fine for the road trip. Who knows, this could’ve been leaking like this for the last year/10k miles or so. Just my two cents.