They're wrong, they got confused because the header column on the data is labeled "age of householder". This is because the data is the ratio of householders who own their homes to total householders, broken down by the age of the householder.

The title of the tables I'm looking at are "Homeownership rates by Age of Householder", which makes it pretty clear what they mean.

https://www.census.gov/housing/hvs/files/qtr423/tab7.xlsx

https://www.census.gov/housing/hvs/data/histtab19.xlsx