I am just talking about my experience signing out general surg path from a wide variety of cases both non-neoplastic and neoplastic. In most non-neoplastic diseases the clinicians already have a fair idea of what the diagnosis is and if you are even a mediocre pathologist you can do pretty well (consider your own example of UIP, the diagnosis is heavily dependent on the HRCT reading? Your other example of dysplasia does not make sense since it comes within the realm of neoplastic? And the third recurrent hep C vs. Rejection just reinforces my point of being descriptive and favoring one thing or the other and throwing the ball in the clinicians court). Again, I will reiterate in non-neoplastic you generate a differential and "favor" one diagnosis over another and the clinicians after taking all sort of data (clinical, radiologic, lab etc) proceed.In cancers, you are the "final" word. If it still is not clear how much more important neoplastic stuff is compared to non-neoplastic stuff, go through the list of things pathologists get sued for. Those are the things that will get you in deep trouble in real world pathology and those are the things you need to be really good at i.e. no chance of error.
As regards, some people not benefiting from a certain fellowship, you cannot make a silk purse out of sow's ears. *****s/slackers can only be taught so much and since the fellowships have to be filled with X number of people, quite a few *****s/slackers sneak in. It definitely does not reflect on the teaching at said program. I will re-iterate for a fellowship year, nothing beats the oncologic path year at MSKCC and Anderson. However, there are some other excellent programs e.g. Mayo etc.
Let me repeat it, as a surgical pathologist you can never see enough of cancer because only one wrong cancer diagnosis can ruin your career and reputation.
And finally about the consult cases at these institutions signed out elsewhere, these cases are the best because you get to see all the mistakes made elsewhere and learn not to make them.
Also the most stressful cases you will face in practice are neoplastic e.g. the late night neuro frozen low grade glioma vs. gliosis, the late night frozen on a lung mass with the question of reactive atypia vs. carcinoma, the pancreatic margin with the question chronic pancreatitis vs. pancreatic cancer. These kind of cases can give you a lot of stress and land you in a lot of trouble if you are wrong. Depending on the case e.g. VIP patient, it may be your last mistake as a pathologist.
In the end, do what feels good to you. I can only relate what I have learnt from experience signing out cases. Best of luck in which ever fellowship you pursue.In the end the most important singular factor will be your inherent potential and drive to excel at diagnosis, because truthfully the "real learning" starts when you start signing out on your own.