Citation needed, well I misread too, it's 16TB. Anyway, it should suffice in the lifespan of Switch.
The real issue is Microsoft limit FAT32 to 32GB on Windows, it doesn't allow you to format a volume bigger than 32GB to FAT32 but can read it if formated by other tools, just to force users to turn to the more patent protected exFAT. SDXC is said to be used together with exFAT, this is the only specification difference, but most devices just use them in FAT32 instead.
No there is no widely adopted exFAT implementation for Linux, because of patent and license issues.
It's sad there is no such thing as a perfect universal file system, while FAT32, with certain flaws, is the only candidate. And nobody seems to be interested to solve that.