For this question to resolve YES, reports/publications/data from a sufficiently conventionally high-status source (e.g. the UN Population Division, the World Bank, the CIA World Factbook, the Population Reference Bureau) need to come out before 2027 claiming that the world's Total Fertility Rate is below 2.1 (replacement level can change depending on mortality rates, but 2.1 is the figure for the purposes of this question).

Not that publications after 2027 that make this claim are not eligible to count towards this question, even if they concern time periods before 2027. The actual claim itself that humanity has fallen below replacement level needs to be made before 2027.

I will use my discretion on what sources I will count. Feel free to ask about sources ahead of time.