If already booked, then you're subject to possible equipment swaps and unlike AA and some other US airlines I think you can't reschedule. BA don't allow changes on this basis.

You have a somewhat low probability of a swap, and I would guess the biggest factor is BA A380 reliability which is common to any route it's on. If you're keen to travel on an A380 then you're in decent shape as things are just now, but even were you able to compute the precise probability statistically, things could go either way on a single outcome. So as with any "what are the chances?" question, the answer becomes very subjective and not all that useful.

I wouldn't be worrying about this personally, since there would be nothing I could do to affect what happens anyway.