https://www.politico.eu/article/queen-elizabeth-death-plan-b...
Is there another monarch alive with this many subjects?
States that recognize the British monarch as head of state: 67 mil (UK) + 38 mil (Canada) + 26 mil (Australia) + 5 mil (New Zealand) + others less than mil people = 136+ mil
So pretty close, but this appears to be a correct statement.