Another uneducated guess…
We will see an electronic 105 within the next 12 months…
it will be the current ultegra Di2 but remade as 105.
I can see a path where Shimano will have
ultegra 12 speed Di2 only
105 11 speed mecanical and Di2
DA with whatever new wireless/semi wireless tech they have.
From a manufacturing standpoint it make sense.
they would rebrand current ultegra as 105. They have to invest 0 to do this. They can command more money for it tho (compared to current 105/ultegra pricepoints).
New would be the Ultegra and DA 12. They share many things so it make sense to have the DA have wireless so they can justify what it will be the stupidly high price.
105 Di2 will probably be close to price to current Ultegra Di2, maybe a few hundred less.
Ultegra 12 Di2 will probably be closer to current DA Di2 (probably abnout half the difference)
and DA Di2 will make the dentist of the world blush with its price.
Again… This is what I would do if I was in charge of Shimano trying to make money.