I expect that a lot of WWDC will be Apple trying to get more developers to build AI products for their platforms, because at the moment, Apple products don't have much AI. The other tech companies have integrated user facing LLM products into a significant part of their ecosystem - Google and Microsoft have them up front and center in search. Apple's AI offerings for end users are what exactly? The camera photos app that does minor tweaks to photos (composing from multiple frames). What else actually is there in the first party ecosystem that significantly leverages AI? Siri is still the same trash it's been for the last 10 years - in fact IMO it's become even less useful, often refusing to even do web searches for me. (I WANT Siri to work very well).
So because their first party AI products are so non-existent, I think WWDC is a desperate attempt by Apple to get third party developers to build compelling AI products. I say desperate because they're already a year behind the competition in this space.
(I can imagine they'll be trying to get developers to build Vision Pro software too, though I hear sales there have collapsed so again, way too little, too late)