If a LO station only has LO services then it will eventually not have
the NR Double Arrow logo, there are some expections to this. There is
more information in the Corporate Design section of the TfL website.

Ah, my apologise. However, I don't think I like this. Assuming that National
Rail railcards are still vaild along with National Rail ticketing and
information, to not have the National Rail symbol strikes me as odd.

Best Wishes,
LEWIS