Such as having an AP hydra or an AP Black Cleaver? (Or maybe variants for those who don't require mana)
I'm just throwing it out there, with how some Battlemages don't have mana resource bars but rely on building tanky to survive, but don't have many options outside Liandry's and Morello and Protobelt, but even then, they lose out on the tools that most Juggernauts have since most of these items were meant for those who scaled off AD, and also primarily used their basic attacks in tandem with their spells.
Also with the inclusion of Sylas and Mordekaiser, most of the AP items are built around the user having range and mana (where Morde and Rumble and Vlad do not), and there aren't a lot of options for some of them. (might also add in AP (melee and ranged) assassins as the options available are the same as normal mages)
Maybe I'm going about this the wrong way, but I'd love to hear from someone who plays these kinds of champs more often and knows more about this than me!