"So I’m clear, if the owner of lands requests that their lands not be mapped on OSM, that’s irrelevant? "

yes
we are mapping Barbra Streisand’s house (and equivalents), mansions of billionaires, Putin's palace, Chinese military bases (and other military bases), North Korean concentration camps and so on.

"DO NOT ENTER, NO TRESPASSING signs" - this kind of thing makes ways eligible for access=no tags - not for deletion of ways

you can create thread at https://community.openstreetmap.org/c/communities/ca/95

> Seems like a legal time bomb to me

see also https://osmfoundation.org/wiki/Terms_of_Use