Yes, Limbo was widely taught (as about .01% of teaching!); where you are getting "when you do away with Limbo that means they would go to hell" I have no idea, especially in view of your closing quote from the Catholic Encyclopedia.
If there is no limbo your choice is heaven or hell, and YOUR church teaches one can not go to heaven unless they are baptized..
154. Q. Is Baptism necessary to salvation?
A. Baptism is necessary to salvation, because without it we cannot enter into the kingdom of heaven.