Check out Tim Bayly on how Rome is positioning itself to send Limbo off to Limbo. Right near the end of this fun article, Tim asks this question of the FV:
Remembering that the Federal Vision is “all about the children,” I’d like to see F-V proponents critically engage the Commission’s report. For instance, would they condemn the Commission’s declaration that the absence of baptism these littles ones suffer is a central factor in the consideration of their eternal destiny?
When I have had to preach the funeral sermon for an infant, stillborn into the covenant, what do I say? I declare, without any ambiguity or doubt at all, that the child is with the Lord in heaven. What warrant do I have for declaring this? The same warrant I had for baptizing that same child, had the child lived. The Westminster Directory for worship says that infants of Christians are Christians, and federally holy. They are saints. If someone dies in that condition, then I have nothing else to declare, and all kinds of promises to encourage the grieving parents.
When it comes to children of unbelievers who die in infancy, I am hopefully agnostic, not having any texts strong enough to support the weight of an argument. But I am confident that the judge of the whole earth will do right, and that sin is not imputed where there is no law, and that salvation is the Lord’s middle name. But this is simply trust in Him, and not confidence about a particular position.