This has always been an interesting theological topic for me. I have looked at it a couple of ways and it always sets up an interesting conclusion with serious ramifications on each side.
From a PR POV.
We can’t go around telling people that unbaptized babies are in hell. Imagine a woman suffering a late miscarriage and someone telling her “Well, hell just got a little more crowded”
But if we offer a hypothesis of “All unbaptized babies go to heaven” we run the risk of admitting that abortionists may very well be the number one producer of saints…
And hanging our moral outrage on the theological Catholic idea of not commuting evil to obtain good.
From a Biblical and Historical POV
There is not one named Saint since the institution of Baptism of Christians that has not been baptized. Not one. Not the holy innocents. (before baptism of salvation) Not the Thief on the Cross. (Arguably before baptism of salvation and no one knows, He theoretically COULD have been Baptized if indeed Jesus was Baptizing for salvation at that time.)
So the Church is and always has been stuck in this arena of ideas. Limbo, while recently given less weight was a good way to navigate the conundrum.
We KNOW God is merciful.
We KNOW God is willing the salvation of every soul.
We KNOW we can break God’s will.
We KNOW God is fair and just.
We do not know the destination of a soul aborted or killed, or that died in the womb or outside of the womb that is unbaptized.
If salvation of infants in and out of the womb is assured through desire. Well, then frankly infant baptism is just a ritual, a symbol and unnecessary. That does not seem to jive with Church teaching on baptism or the Biblical words of Jesus himself.
We live in a day and age where infant baptism can be a production. A show. It took 8 months for my oldest daughter to be baptized at our parish. Mandated classes, held only so often, a schedule to abide by and a whole party to plan.

But yet now that we have established ourselves as a “legitimate” Catholic family all I do is call the Parish office and my youngest 3 were baptized within 2 weeks of birth. There is something not right with that.
Is it possible for an unbaptized baby to go to heaven. Heck yeah it is! our Church teaches that it may happen. However, what we do know FOR SURE is the path to heaven laid out for us by the Saints, the Church, and the Word of God itself. And that should cause us to have an urgency to baptize and evangelize that many Catholics desperately lack.