Um...well typically after this website creates a thread about the next one piece magazine a wiki page with all the same information will be created. And back in April, the Wiki said September 4th, just like this thread did, however, when I went back on there to see if what devil fruits had finally been revealed, I noticed the gate had changed from September 4th to December 11th. So to make sure that it wasn't just some butthead playing a prank by changing the date I looked on the Spanish and Japanese versions as well, and they also were changed to December 11th.
As for the rest we're to assume the devil Fruits are gonna fall of the one piece heroines. And there are devil fruit ladies on the cover of the one piece heroin's promotional image which was the color spread from chapter 1084. Meaning, there's a strong possibility one of them are the devil fruit in question. However Oda does like to throw curveballs by making holiday or birthday month Devil fruit reveals. So I looked through the SBS's for all female, December birthdays and those who have an unknown birthday and I listed those.
But at the end of the day, this is just my prediction based on his pattern. Oda could throw a complete curveball and do 2 devil. Fruits that are absolutely nowhere on the list. Although I would say that it would kind of messed up to have a magazine dedicated to the one piece heroines, and then throw 2 guy devil fruits in there. But if that's how Oda wants to break the pattern, it's a very real possibility.