Yes its a bit of a cop out response in my opinion. Definitely agree with you that it should be added though, along with Bethnal Green LO to Whitechapel. Manor House to Harringay Green Lanes probably makes more of a difference if you want to go towards Gospel Oak on the GOBLIN, as going eastbound, it is possible to go 1 stop more to Finsbury Park and take the Victoria to connect at Blackhorse Road.