You aren't missing anything. Your A/~A pair is inclusive, because you have properly (if informally) stated A as, "I am an electric elk named Simon", and your ~A as, "~(I am an electric elk named Simon)".
You did not, for instance, try to define ~A in terms of what you are, e.g., "I am a tapir (which has occasionally been mistaken for an elk) named Fred (which kinda sounds like Simon)".
Mr. Savage could define, for instance, A as, "My 'self' lives only once, and that for a limited time".
If he would then define ~A as, "~(My 'self' will live only once, and that for a limited time)", he would still have an uphill row to hoe, but it would not be due to improper construction.
Instead, as I understand it, Mr. Savage is now defining ~A as, "I am either immortal, or exist more than once (which amounts to 'immortality')". (Note, for instance, that a "self" that lived only once, but was extinguished by mischance before the end of eternity, is included in neither Mr. Savage's A, nor his ~A.)