As a big fan of John Barrowman and Captain Jack, I’m choosing to remain optimistic and that he’ll not only be featured but that this could be some backdoor pilot for a Torchwood revival!
While The BBC is often unwilling to comment on these matters, it does need to be said that the fact Captain Jack is appearing in a tie-in Doctor Who novel does not necessarily guarantee his involvement in the episode it’s referencing.
Or, Jack could only play a small part in the actual adventure, which would justify fans buying a tie-in novel to see the full scope of what he got into.