Sorry, but it doesn't appear so. The following is from a WDW Press Release:
Mischief Abounds in Stitch's Great Escape!
The Academy Award-nominated film Lilo & Stitch inspires the new Magic Kingdom attraction Stitchs Great Escape! scheduled to open in late 2004.
A pre-quel set shortly before the events of the hit Disney motion picture Lilo & Stitch, the family-friendly adventure in Tomorrowland will showcase the mayhem caused by the mischievous Experiment 626 -- a.k.a. Stitch -- when first discovered in the Galactic Federation.
Entering Stitchs Great Escape! Magic Kingdom guests are recruited by the Galactic Federation Grand Councilwoman to provide additional security for a captured alien whose reputation for being extremely difficult has preceded him. Even so, authorities underestimate Stitchs capacity for playful disobedience, causing havoc to erupt with guests caught in the middle of the fun.
Stitchs Great Escape! will feature some of the most sophisticated Audio-Animatronics® technology ever developed by Walt Disney Imagineering.
Stitchs Great Escape! replaces The ExtraTERRORestrial Alien Encounter, which will close later this month.