Tristán White wrote:

But what amazes me is that it hasn't been changed. Have the staff, the
Manager of the Northern Line (and the Jubilee Line for that matter),
completely not realised that this is the case? Do they know but can't
be arsed (strange, as it's big enough and it's the first thing you
see when you go down the stairs). There's no evidence of a sticker
with the changes having been removed by someone.

LUL have never been on the ball with keeping their signage up to date. Look
how many signs there are that still give directions to "British Rail", ten
years after it disappeared. The same thing applied to all the announcements
about changing for "Network SouthEast", which disappeared on 1st April 1994,
two years before BR.