Yeah the occasional formatting recommended, is due to the read / write nature of dashcams, so the file allocation table can get fragmented and that can slow down the performance of the memory card.
Old PC users will also know this from computers with windows for OS back in the day, this have changed now due to technologies in hard drives and our operating system.
Keep a eye on the footage your dashcam record, and do a in camera format every 1-2-3 months, and you have done all you can to ensure a good dashcam experience.
Buy a cheap dashcam and a cheap memory card, put it in your car and forget about it, and you are heading for a very bad dashcam experience.