TL;DR: John Byrne has stated that there will be massive news coming this Thursday regarding his X-Men fancomic X-Men: Elsewhen (which he had previously teased about last October). Thursday happens to be the same day that Marvel will have a dedicated X-Men panel at SDCC, and the rumored announcement will be that he and Cebulski have worked out a deal so that Elsewhen is going to be officially published by Marvel.

>https://bleedingcool.com/comics/john-byrnes-x-men-elsewhen-finally-coming-to-marvel-comics/