In Digimon 02 Ryo again makes a "blink-and-you'll-miss-him" appearance in two episodes concerning Ken's
past. He's the kid in purple traveling with Ken through the deserts of the Digital World. He first appears
in episode #23 'When the Digivice is Infected with Darkness' (aka 'Genesis of Evil') and again in episode
#43 'Attack of the Demon Corps' (aka 'Invasion of the Daemon Corps').
We see him (briefly) walking with Ken in episode 23. In episode 43 he's the kid Ken pushes away from the dark seeds/spores flying towards them.
No information is given about him other than Ken apparently met him when he first visited the Digital World and met Wormmon (and that's just speculation from what is shown to the viewers). The flashbacks themselves were adapted from the Tag Tamers Wonderswan game which was created as Ken's backstory.