The catholic church teaches of original sin, the kind that adam and eve bestowed upon the entire human race. When I attended catholic school, we were taught that if an infant was NOT baptized, to remove original sin, they went to LIMBO, for a period of 'undisclosed' time to pay for the original sin, Now, New belief is stating otherwise??? weird....
Actually, this is the way that doctrine has ALWAYS developed. Even such beliefs that we take for granted as "Jesus is of the same essence as God" was not always a slam-dunk theologically. It took CENTURIES before the Church actually defined the issue and rejected teachings that went against the mainstream of Catholicism. Thus, theologians are free to teach what they believe is the truth on issues that are not defined yet, as long as they are within the realm of allowable teachings. Thus, Limbo is a speculative teaching, since the Church hadn't defined what happens to babies not baptized. There seemed to be a question as a result of St. Augustine's "mass damnatia" idea - which specifically condemns such infants to hell. The Church specifically overruled that idea, but no subsequent answer was provided. Thus, the future speculation that was called Limbo.
Limbo was never an official teaching. It is probably over-zealous nuns and priests who pushed the idea forward, perhaps under the influence of Jansenism, perhaps under the misconceived idea of focusing on the Decalogue in moral theology (which then focuses on rules and regulations, rather than on love - the supreme virtue). Who can say. But the Church is not stating a new belief. It is still "speculating". Until the Church comes forward and proclaims one way or the other in an official release of teaching, one can still hold to Limbo and not be considered a heretic.
Regards
I have questions. If a catholic lost a child and was told the child was in Limbo, wouldn't that parent feel it was necessary to remain faithful to the RC church so that the child would see heaven? That is wouldn't they want to do all the appropriate catholic duties - masses, prayers, indulgences, etc. - to move that child along. What would happen to that child if the parent left the church? How many catholics who believed this "teaching" have felt obligated?