This begs the question about whether, in the case of a change to wetlease after initially booking, you would have the right to cancel or reroute.

Like many here, I always understood that wetlease basically meant you were getting exactly the same product, albeit in a differently painted plane. If that's not the case, then it sounds like it could be a material change. The (almost) limitless hand baggage weight with BA is clearly an attraction to many.

At the very least, you would expect BA to clearly set out what is different up front when the wetlease is known at point of booking.