It isn't inevitable. It's only inevitable if you care about timestamps being correct which for many users of those ABIs doesn't matter too much - they e.g. only care about relative time.
It also isn't strictly necessary until 2038 (depending on your needs for future timestamps) so you'd be creating problems now for people who might have migrated to something else in the 13 years that the current solution will still work for.
It also isn't strictly necessary until 2038 (depending on your needs for future timestamps) so you'd be creating problems now for people who might have migrated to something else in the 13 years that the current solution will still work for.