Connie left on her own accord because she was perennially at loggerheads with Devyn.

Why did they replace Connie though? I wish they kept her as I could have totally seen her be the next Stacy and stay on for a few more years.

Kids Incorporated was kind of like Menudo or the Vienna Boys Choir. Once you got facial hair or grew boobs or your voice changed dramatically, your ass was O.W.T.
"No my brotha, you got ta buy yo OWN!"

they were removed because of their age as soon as they hit 16 or 17 they had to leave the show. some did get explained but the rest never did i hated it when stacy left she was my favorite.
yeah i said it so..

Mickey:said that he moved, Gloria:went to music school, Kid:exchange student, Renee:went to London for a year, Connie and Ryan:never explained, Riley:went to college, Devyn, Richie, and Stacy:never explained. Eric:moved. Robin:never explained. Jared:never explained

LMAO! Jerry wasn't in just one episode, he was in the entire 1st season & supposedly left due to creative differences with the creators of the show.
I feel like I'm in Derek Zoolander's Center For Kids Who Can't Read (or spell) That Good

I sadly didn't mention him because for me (personally) he only was there for 1st episode ~ don't even recall his other ep's. Also I stated she was 1st I (knew) to have left perhaps cuz of her age. I mainly only knew of Martika, The Kid, and the other girls (whom later became famous for forming a group outside this show).
So if he lasted a season I honestly missed such and perhaps could explain why I didn't state him as 1st to leave (although he was) but not sure it was due to his age but perhaps other situation.
Poop in his hand Poop in his hand

nO SHE WASNT. Jerry was the first to leave. Martika was the 2nd.
Point of No Return

Wish I could assist but see another poster gave a few answers. Personally I started to laugh when I read the initial subject question because it made me think of the 80's group Menudo who kept replacing members due to them aging.
I use to assume same with this show ~ in beginning was Martika whom looked like the oldest sister of the group and then she soon left. Truth was due to the singer coming out with her own personal music but still was interesting that she was one of the 1st to leave.
Poop in his hand Poop in his hand

I think Gloria went to a music school or something. Kid became an exchange student. Renee went to London for a year.