Oh, I see what you mean.

I checked my lot:
Minolta Srt-100x, Srt-101, XM, X-700: reverse curl;
Nikon FE2: reverse curl;
Voigtländer Bessa-L: reverse curl;
Voigtländer Vito CLR: straight curl;
Canon Canonet (quick load): straight curl;
Yashica T-3: I suppose straight curl (automatic load).

I usually don't process my films immediately after having extracted the cartridge from the camera. I've never seen a film with a reverse curl so far.

I didn't understand this reverse curl thing. I thought that if you open the back of the camera by mistake, it's better if the back of the film faces light.