Maxpod
I think you’ll find this is a highly contentious issue so stand by, possibly, for lots of comments. If you still have the letter authorising your PICUS then what is wrong with you continuing to do so? If the training department want to change the rules for all FOs then presumably they’ll change the training manual and/or issue a memo or notice to that effect. While you’re there have a look for yourself at the training documents to see what guidance is there.
I have a honest question for you though. What advantage is there to you in logging PICUS? Good luck in your career. I’m sure they’ll be pilots jealous of the fact that you aren’t flying many hours. Enjoy the time off! Hope that helps.