I mean, selection is always against antinatalism - even within early Christianity.

For example:

A woman in the crowd said to him, "Lucky are the womb that bore you and the breasts that fed you."

He said to [her], "Lucky are those who have heard the word of the Father and have truly kept it. For there will be days when you will say, 'Lucky are the womb that has not conceived and the breasts that have not given milk.'"

• Gospel of Thomas saying 79

You see the call and response broken up into two separated parts in Luke, but the mirroring indicates they probably went together originally.

The antinatalism isn't just here, it's also in surviving fragments of a lost work followers of the above also followed:

Salome saith: Until when shall men continue to die? [...] and it is advisedly that the Lord makes an answer: So long as women bear children. [...]

And why do not they who walk by anything rather than the true rule of the Gospel go on to quote the rest of that which was said to Salome: for when she had said, 'I have done well, then, in not bearing children?' (as if childbearing were not the right thing to accept)

• The Gospel of the Egyptians as preserved in Clem. Alex. Strom. iii. 9. 64 & 66

So there's a bit of irony in this person making fun of beliefs involving not having kids dying out when there's a decent chance the original advice of the person they intend to believe over all others was actually saying the same thing and the proponents of that group thinned out over the years since his death leaving cannonical Christianity to thrive due to literal survivorship bias.

Amusingly, this group's alleged teachings overlap with modern 'atheism' in a number of other things too, such as their inclusion of atomism into their beliefs and entertaining the rejection of intelligent design in favor of Lucretius's naturalism.