The attendee figure will be a Deluxe with a new head.
Of their at-show toys, one is going to be their centerpiece toy for BotCon, which is not a Combiner Wars toy.... and they will be making it extra limited to drive demand. *snip*
Of the other at-show toys there will some Combiners, and a Generations toy using "not American" tooling (so a mould released in Japan).
So with this knowledge we know that the exclusives for this BotCon set has more new heads than any other, with 6 confirmed (1 for Ravage, Tarantulas, Ramhorn, the Attendee Figure, and 2 for Sea Clamp)
Any centerpiece figure is likely to have a new head, as what could be made that could be considered a centerpiece figure and not get some form of new tooling. Potentially pushing the total to 7 new heads for this set.
As was mentioned, we have a few Japanese exclusive Generations (thereabouts) tooling. This includes Nightbird, Slipstream, Blackarachnia, and Deluxe Groove (if you count Unite Warriors / Combiner Wars).
So who do we think the centerpiece is? A centerpiece figure says to me something Voyager scale or bigger.
What about the attendee figure? Who is this Japanese only tooling figure?
Some of the other souvenirs are Combiner Wars, who do you think we'll see for CW figures? I wouldn't be surprised if the Ravage head was reused as a Tigatron myself.