If we consider that a two class aircraft with no fancy dan Y+ offering was making profits* then perhaps Skipness we might be able to suggest that only clowns would change a "winning" formula, especially considering the lack of prominence the route was given. Should the 787 come in as advertised with much better fuel consumption that the 763 or A330 then I would suggest that however marginal a route is at present, it's profitability would in theory be increased. Yes the long-haul routes on offer are predominantly going to hubs but notice how few offer J, Y+ and Y. Whatever revenue accrued from poorly patronised Y+ would be beaten by not having that offering but with a couple of extra rows of "ordinary" Y.
* At least we can safely say it was making profits given the mantra over that route's withdrawal that BA is not a charity!