A datapoint. I got through to You First very quickly after my ex-CPT on the 27th popped up on expertflyer as cancelled, mid afternoon. The agent couldn't see the cancellation nor could MMB in ba.com; however, a supervisor could!
Initially got offered the next day's BA flight which is no use time wise, was then offered a Oneworld re-route and QR worked for me. I end up losing half a day in Cape Town but fine in the overall scheme of things. Was very very quickly sorted. The re-booking e-mail confirmation was through in 15 minutes …. followed two hours later by the original cancellation e-mail!!
Very limited F options from CPT, more so as EK are not on the re-book list. BA were not keen to go with LH at this time, but I didn't press it as the QR option is overall pretty decent. The flights do seem to be filling up fast looking in 8 hours later.
Overall, the You First encounter exceeded my expectations today. Shame about the circumstances.