Big boats tend to be faster than small boats, so the big cats should become foilborne in less wind than Moths - provided taht their total density (total boat weight/total boat volume) is lower than that of a Moth. For comparison, the total density of an ORMA Open 60 is more or less the same as styrofoam.

If the venue would be in an area of strong winds, foils would certainly be used for stability and very likely for 100% foilborne sailing downwind. Banana foils to assist stability could be seen in BMW Oracle since it saw daylight.

On the other hand, if the race will be in a light wind area - as Alinghi's design seems to indicate - the banana foils won't be necessary and 100% foilborne downwind sailing will be unlikely.

Let's wait and see.