Written by We leave for Scotland via London Wednesday evening, on BA 102. We arrive, according to British Airways’ information, at Terminal 4. I consider this a good thing, given that Terminal 5 is a living nightmare right now.
However, that said, there is NOTHING in the news about how the other terminals are faring at Heathrow airport. Does anyone know what baggage delays — if any — exist at the other terminals? Pileups at one surely must affect the others. Any and all pointers are appreciated! 
Sometimes, you need to get your own answers. So I just checked with British Airways (a very helpful set of people on the phone, I must say!), who said (and this is paraphrased) that Terminal 4 (and presumably Terminals 1, 2, and 3) do not have the same problems as Terminal 5.
Although technically isolated, that does not preclude the possibility of delayed baggage for a zillion other reasons.
So fingers (and toes) are suitably crossed that this goes well.