As far as I know they are all airtight, unless the lids are somehow too loose to fit snugly.
Fuji uses the same type of canister for all its films (lid colour may vary, and some films seem to have beige opaque canisters, but they are all of the same design). Kodak uses the same canister for all its films as well.
Re-checked and you are correct. My assumption, now false, was made as a result of an alternative use of empty canisters.. Alkaseltzer rockets with my grandsons. I first tried Kodak cans since I have a ton of them. It never built sufficient pressure and just oozed and bubbled out from under the lid. Then tried a Fugi canister I had and it worked great. The boys thought was pretty cool. So it turns out it's just a matter of how tightly the lids are secured. See, I said this wasn't exactly film related.