He was always quite an attraction at the beginning of the reptile world complex, so it'll be a shame to see him gone, although i'm excited to know he'll have the chance to breed over at Adelaide!
They plan to have Komodo's in their new Reptile and Amphibian centre, which is scheduled to begin construction very soon. It's planned to be opened late next year.
Since they plan to demolish their current reptile world, I wouldn't be suprised if they just leave the enclosure empty. There's no point of filling up the enclosure temporarily, unless they have an animal/species that needs an enclosure. Lace monitors would be a good replacement, considering they're like a smaller version of the Komodo Dragon.
The former Komodo Dragon exhibit now houses Rhinoceros Iguana.