The theory that "SARS-CoV-2 leaked from the Wuhan lab" overlaps some with the theory that "SARS-CoV-2 was man-made", but they're not the same thing. According to the article Facebook's policy change is towards posts saying "SARS-CoV-2 was man-made". Did Facebook's policy ban posts which supported the "lab leak" theory but didn't claim the virus was "man-made"?
It's not clear to me what you mean by "they don't overlap at all". If I create a truth table for the two binary possibilities of 'leaked?' and 'created?', I get something like this:
Created, Leaked: It was created in a lab, and accidentally got out.
Not Created, Leaked: It was being studied in a lab, and accidentally got out.
Created, Not Leaked: It was created in a lab and deliberately released (the biowarfare hypothesis.)
Not Created, Not Leaked: The lab had nothing to do with it at all (the wet market hypothesis.)
Created/leaked are independent, but since both or either could be true or false, there seems to be 'overlap.'
Facebook's April 2020 covid-19 policy notice only mentions "man-made". https://about.fb.com/news/2020/04/covid-19-misinfo-update/