@Captain:
A sticker index is the only reasonable way to do any kind of table of contents for these folios but tbh they're probably all gonna remain on the sticker sheet forever because I'll be too worried I'll rearrange things later.
Interested to see what new cards we get. Hopefully we get a few new faces as well as double-ups for existing characters. At this point Luffy's almost definitely getting a kid card, since Sabo and now Ace also have. At a guess, they might be giving us some of the prominent characters from the early acts of Wano now as a hype thing. The colour manga let another release window go by with no announcements, so it'd make sense if the colourists had been pulled back to do some new cards. Fingers crossed.
If the index pack goes by the same card count as previous packs than there will likely be two character cards in the pack (10 index sheets, 4 sticker sheets, 2 character cards). 10 year old Ace has been confirmed for this pack, so possibly 7 year old Luffy (I might be off with the age) will be the other character that will be part of the pack, rounding out the three brothers. But who knows, maybe the card count for the index pack will be higher than the regular packs. I hope so, because I really don't want to wait for the third binder's stater pack for character cards that were passed over in previous packs (ex. Nola, Yokozuna, the Macro Pirates, Opera, Galette, and possibly the Charlotte Decuplets and more Foxy Pirates).
Also I believe you mentioned in a previous post that Oda didn't like the idea of promo and event cards, so if there is a second index pack it would seem like good opportunity to re-release the Luffytaro and Zorojuro cards, just like they did with the Law skill card in the Punk Hazard pack.