The societal impacts I see long term from the ability and social permission to choose childlessness:
* both any biological factors and memes that encourage childlessness will be weeded out of the population in two generations, and we’re already half way there
* the religious who favor families may be a minority in the West now but will grow in numbers and as a percentage of society because the future belongs to those who show up; ideally, that isn’t due to foreign imports but domestic production
Other than the Amish and Mennonites, and to some extent the Mormons, the Christian world has not produced a large community that will preserve their cultural and religious inheritance.