Quick Note: I said condensation is how the fluid gets in, I don't think this is right. I believe brake fluid naturally absorbs it from the air, anyone out there with more knowledge please feel free to correct me.
Check water percentage and color of the fluid. Even if the water percentage is ok, generally its a good idea to to change the fluid if its been like 5 years. Idk how long u had the car but u can probably get away with not changing the fluid for another 10k miles or a year. But yea i would consider changing it next year.
You are right. Brake fluid is Hygroscopic and absorbs water from the environment. On average it's been said a vehicle can absorb 1.5% moisture each year. It's good to check brake fluid each year, specially on older vehicles. Some recommend changing brake fluid every 5 years.
Ye well, I mean, who's not a scammer these days? I got this little device myself, learnt to change filters, check tyres, pressure and oil level/colour, but that's all I can do without getting to passionate about things lol