Year after effect is a good theory, but in Elo's case I'd throw it out the door. Its not really the year after, its just in general when a pitcher has thrown a lot more innings then they have at any other time in their career.
In regards to Elo, he's a veteran and has pitched a while and his body is matured and developed. This sympton should not get him. While his numbers will likely get worse, In this case I don't think he fits in with this phenomenon.