True but it was a real consideration for a surprisingly long time. And you still find a lot of lawnmowers that tell you not to use E mixes in them, I am not sure why (my guess are either they are being super cheap on the rubber or just acknowledging the fact that lawnmowers tend to sit and the E mixes sitting tends to corrode things and go bad.)
Literally nothing keeps the power equipment industry from making their carb parts out of components that won't rust except being cheap asses and wanting to sell parts and kits and keep their dealers happy with repair business.