Quite common when diversions occur. I'm currently on 1015 Waterloo to Westbury.
Yes, but I don't remember them being booked to call, only to reverse.
The CIS▸ systems are not acknowledging the Westbury stop today even though the journey planners show it and I was sold an advance fare on the service.
It's happened before and I have used it. In September 2015 (19th according to photo dates) I caught an
SWT▸ service from Woking to Bath. The return journey involved an
FGW▸ train to Westbury where I boarded the SWT train back to Woking. It was showing on journey planners although I do recall it was 20 - 30 minutes late and disappeared off the CIS screens shortly after it was due.