It's a nonsense plotpoint, because the Naga were basically free for 10.000 to find a solution for their addiction, but then rely on someone who was instrumental in destroying their initial plans to cure them.
And what's his solution? *gasp* Take it from demons, which is something that anyone who participated in the WotA should figure out.
By comparison, the blood elves addiction is caused by the destruction of the Sunwell, which was a recent event, it's not like they had time to figure alternatives for over 10.000 years.
That's why i think it makes little sense, the Naga are an ancient race who must've suffered from this addiction for a huge ass time and Illidan's proposed solution isn't exactly a groundbreaking one to the former Highborne.
Disregarding that it's never brought up again, whereas this whole magic addiction thing for Blood elves carried over into Classic / TBC.