Remember - at the time Commodore died in 1994, LCD screens were small, low quality and expensive. "Portables" were bulky and heavy. It would have been stupid for Commodore to attempt to release an Amiga laptop at that time. Besides, they would have had to start development in 1992 (when LCDs were even more expensive) to have released it before their demise in 1994.
I've seen a few attempts by users to make one around 1997. I think they took a hacked up A1200 motherboard (or was it A600?) and crammed it into a Compaq notebook. It wasn't a pretty sight.