I wonder if hobbyists would be able to pick up this data using some sort of RF capture device.

Picking it up is no problem for some specialists in the (ham) radio scene. They are mastering X- and S-band stuff so good that even the NASA asked them to join in some observations in the past.

But: Meteosat is very famous for encrypting their stuff.

See my comment above re a CCC.de video from 38C3.