One thing it's worth noting is that Nardole only knows about River. As in he knows what happened with River. So it's natural for him to assume that the Doctor is dealing specifically with River based angst, whereas for 12 it's more Clara, then River back to back all mixed together. But then I feel like I'm clutching at straws, the episode was quite specific.
Yeah, sometimes I do feel like I’m clutching at straws a bit (or my version, wearing the tin foil hat), but mostly it’s because I feel like the writing can be and is better than what the general audience gives it credit for. :P
However, I’d argue that the “specifics” is only when “24 years” is brought up, which I saw as more of a firm wrap on THORS than anything else. Call me crazy, but whatever, the Doctor has had more important relationships in his life.
(See asks here and here for me talking about stuff with the Doctor and romance and ~feelings~.)
