Not clear, but will this effect the line from Willesden Jnctn via Olympia to
Clapham Jnctn? I have found this a very handy way of cutting across west London
and when I made a diversion via this route(Willesden -Olympia then bus) to get
to Chiswick during the tube strike the trains were packed to the gunwhales(?)
(Likwise of course the alternative route via Willesden Jncn to Gunnersbury).
If the line is unaffected it does offer another way from Watford, as you can
change at Willesden Jnctn.
But anything which forces more people into central London does seem
retrogressive, and Victoria platforms are sometimes closed for intervals during
the rush hours because they are so overcrowded.