If you chose to delay yourself by waiting for the next direct service then I don't see any reason why the TOC shouldn't do that. Obviously that depends on whether a passenger would know that catching a service that doesn't go to their intended destination would reduce the delay.
It is quite common for some companies to advise based on direct trains. For example on one occasion I was waiting for an xx30 departure from Birmingham New Street to Gloucester on CrossCountry, which was cancelled at short notice. I spoke to the ticket office staff, who advised me that the next Gloucester service was the one an hour behind. I waited in a café for that train and made a claim for an hour's delay, which was paid, although after some prevarication.
I was aware that there was an alternative way to Gloucester by taking the xx42 service to Cheltenham Spa and then changing to a GWR service. I didn't undertake to use that option though because I thought it was better to follow the advice I had been given by the station staff. It was also not made clear to me whether my ticket would be accepted by GWR on their Cheltenham Spa to Gloucester train, as this would not have normally been valid.
If CrossCountry had made the arrangement for me and others going to Gloucester to use the departure 12 minutes later to Cheltenham Spa and then change either to the GWR train or road transport, the delay to the arrival time in Gloucester would have been less than half an hour, so no compensation would have been due.
