As Kuro says, we can't promise anything. But, I can at least let you guys know my expectations.
I would really like to think that because of ORAS and the Essentials update (the last Essentials update we're planning on doing, in fact) we won't have another six month development time before the final episode. However, the average development time is probably going to go up because of three things:
AI improvements
System Bug-fixes
Animations
Each of them is just now coming into focus for their own reasons, but all of them are time consuming. I'll go through one by one.
AI is always a work in progress, but the Essentials AI was shipped incomplete for the start. Never mind how much of the formula we've already had to gut and tone up to make Singles AI' passable. E16 will be correcting the structure to make Doubles' AI actually function (it currently may as well not be functioning at all). After that, we have the task of actually completing the AI. As it is set up, that will not be difficult work, but it will be time-consuming work because we will have to add code for every move effect and all of the ideal situations to use it in, including Field Effects. Now, the AI will never be so good that it can make predictions and plays like an actual competitive battler-- that's just not in the current structure's capability-- but we can at least make sure it knows that if it has full HP and a focus sash, it better go for the turn one Shell Smash, or if it's fighting in the Rainbow Field (for some reason) that spamming flinch moves is probably going to work out for it. That work will be split between E17 and 18 so that it can be tested thoroughly for any errors to be fixed in 19.
When I say System Bug Fixes, I'm specifically referring to any system that makes the game a Pokemon game. 95% of the time this means the battle system, but also includes stuff like the Pokedex or HMs. It does NOT include anything relating to puzzles, or overworld/story events. So, the battle system itself was incomplete until E15, remember. Now that it -is- complete, we're able to turn our attention to the AI, as above, and just as importantly, patching up all the holes. If you've seen our Known Bug list you'll know that we have, what, ~175 things to fix? Some of it is minor, some of it not so much. We've done a little bit here and there, but I expect to specifically target and lock down those bugs as objectives over the next three episodes, again, so that any final changes can be made in time for the E19 final release. We definitely do not want to be making large scale changes in E19 as those are likely to introduce more bugs, so we will probably be looking at doing -those- in E17, and clean-up + minor things in E18.
Finally, animations. I was originally going to delegate Animations to the community as their project following the shiny sprite completion, because there's very little previous knowledge needed to actually use the Debug Animation Editor. However, after looking at the calibur of our current resources and animations, I've decided that I will probably have to do this myself in order to make sure everything is consistent, and quality. This will probably take a great deal of time because it must be done occasionally multiple times, for each of our ~700 moves. This will be split up over the next three episodes as well, with animations in E19 -potentially- being focused on Field Effect specific animations.
Since I haven't really gotten into the animations yet I can't say how long those are going to take me to do. I don't have a sense of them. But, they will probably be the biggest culprit in terms of extending development time. Assuming they are't -too- tedious, it might only be an extra month or something per episode. The other stuff will still be significant but can largely be delegated to people like Kuro and Jeriberry, meaning that can happen alongside development. So while the average development time has been around 3 months in the past, we'll probably see it pop up to 4 or 5, with the final episode taking even longer for final bug fixes + post game content (which is going to have the sidequest syndrome again). In short, my best guess would be mid 2017.
At least, that's my goal. It's always subject to change.