Little correction, the A10X is a 6 core CPUA9X was a 2 Core CPU
A10X was a 4 Core CPU (But lacks HMP heterogeneous multiple processing)
(There was no A11X)
A12X was a 8 Core CPU and a huge advancement in everway.
IMO Apple will skip the A13X and announce next year, a 5G A14X CPU in partnership with Qualcomm for iPhone 5G and iPad Pro 5G
There is No point in designing a new chipset and SoC for a low selling relatively iPad Pro line. The 2019 iPhone will get a A13 but no 5G that’s all.
A11 was a skip year, it had no A11X brother same as A13 it will have no A13X Brother.
I don’t see the A13X/A14X having more than 8 (or maybe 10 but I doubt it) cores, and I think the focus will be on getting clock speeds up. I expect 6 gigs of RAM across the board or maybe 8 on the highest end option. A stronger chassis would be great too
As for the release I’m thinking early 2020 but ya never know.