Bored so going over this again.
>Attack
Two different arrow types on it. So at best it's both Keyblade switching and a second menu page, and at worst it's just one of those things. Left to menu swap, right to blade swap. Little icon calls back to KH2's version.
>Magic
We know nothing.
>Items
There's an icon with a number, probably a little QoL update showing how many you got left total without checking.
>Build
We know more than magic, but still practically nothing. Maybe that bar above the whole thing is a timer for whatever you use with it, and that square is it's associated icon.
>Summon/Link/etc.
Probably on the second page. It's always had a dedicated menu somewhere in the UI for this series, even when forms, attractions, and team attacks didn't. Can't imagine it's only thing on there, so maybe limits/team attacks are also in a menu again. Maybe "Magic" swaps to "Limit" and "Build" swaps to "Summon". "Item" swaps to "Attraction Flow"

Please give us news, Nomura.