As I explained
above (post #469 on p. 32), TCC is not an official ISU event in the same sense that JGPs (for example) and WTT are official ISU events.
If you look at the listings on the official ISU calendar (and//or at the respective event pages for TCC and WTT on the ISU site), the difference is clear.
And TCC is not part of the Challenger series.
TCC is an ISU-recognized event in the same sense that Gardena Spring Trophy (for example) and many other comps are ISU-recognized events. But scores from Gardena and other comps like it do not count for official ISU PBs.
All of that said, I will repeat that I am not 100% sure ... could be wrong.
But my two cents are that I highly doubt that TCC scores will count for official ISU SBs or PBs.
When the ISU received queries on Twitter whether it would provide streaming of TCC, the ISU's pointed reply was that TCC is a US Figure Skating comp.
My interpretation of the subtext from @ISU_Figure was something like, "You're barking up the wrong tree. TCC is not the ISU's comp -- so no reason that we would be streaming it. You should be asking US Figure Skating about streaming."