I agree, gftn. I would even go further and say that Shoma can not only carry a warhorse, he can interpret it in new ways that haven't been done before, and that's an amazing skill to have. The problem with warhorses in general is that they are usually used because they are easier to interpret than a never been done piece of music. Everyone knows what to expect when a skater skates to Carmen. If you really want to make a piece your own, and be remembered for the ages, do not use a warhorse. But not everyone is able to skate to something new and fresh. This is not about Shoma but the pair Savchenko/Massot skated to a soundtrack that hasn't (as far as I know) been used for skating before. Sui/Han chose the ever reliable Turandot. Mistakes aside, you will have heard many people said that Savchenko/Massot would go down in the history with one of the best pairs programs ever. If Sui/Han had won with Turandot, it wouldn't have been the best pair program ever, it would just have been another skate of Turandot. In my opinion they rested on their laurels and played it safe which played part in their loss too. They were a fresh and modern pair, they have the goods to skate to something new and did it before, but not here.
Concerning POTO, the fear comes from the fact that this is one of the few pieces of music we have an opinion on from Shoma. (Other than the Kimi no na wa soundtrack). He watched his biggest idol Daisuke Takahashi skate to it at Worlds and he was a flower boy at japanese Nationals when Daisuke skated to it. It moved him deeply and he mentioned it quite a bit. So it might be his secret wish to also skate to POTO. If he does, I'm sure he could do it and be great at it. I'd rather he not, but there are a few things I hate even more than POTO so should he decide on POTO one day, at least it's not...well, something else I won't write down here. I just do not want a version with lyrics. Come to think of it, Shoma is one of the few (only?) men who has skated to a piece from a female singer (Milva). Interesting. I think normally the male skaters use male singers for their program. Pretty cool.
Regarding Time after Time, I don't think he dropped it. He will probably skate to it again, either in later shows, but definitely in exhibition galas in the season. It might be another switch situation between Time after Time/Great Spirit like with See you again/This Town. Why he skates to Great Spirit now all the time? Granted this is only speculation on my part. He said at PIW he likes Great Spirit better. It's a much more fun program than Time after Time. Shoma enjoys skating to it, he's young, he's into the club thing. So he decides, I'm skating to my fun exhibition, because it's my favourite. And perhaps the audience reaction was better? I mean, this is piece that gets the crowd going. Just my two cents on the topic. I think it's harder to entertain with pieces like La vie en rose or Time after Time. This mellow thing - you gotta be in the mood, and maybe Shoma is in the summer club mood, atm.