The probability of a non-Kodak Kodachrome development process being introduced is rather remote.
How a long a latent image may be viable on a particular emulsion is quite variable. I recently processed some test rolls of Fuji Acros that I exposed several years ago, and the image was absolutely fine. Another fellow had horrible problems with Ilford Pan-F, with the images having faded almost completely away. As it turns out, Pan-F must be processed ASAP, and it's a known problem with the emulsion.
Very probably your film is fine.