October (as per Joe Anderson's tweet) is the deadline the Council set Everton to prove that they have funds (£250m plus) and a plan for WHP. If they haven't at that point, the Council are well and truly moving on. As far as I'm aware, it was the Council who leaked Everton's interest in the first place to try and hurry Everton into doing something. Everton's scheme had been to have a loose plan to do something on the land in order to prove to potential investors there was scope for a stadium.
But the Council weren't happy to just let Everton mess about and pretend to do something and keep others waiting - so have tried to force Everton to put up or shut up - hence the leaking of the possible scheme and now the October deadline.
So far there's been no evidence whatsoever that Everton have any genuine/serious plans for the site.
I think we can all guess how this turns out.