My hope is that while working on the next iteration, they find the buggy code causing the errors and go back and fix it in DBC 17 if they can. It sounds like they don't have any more funding for a stand alone patch for DBC 17, but I feel if they find the cause while working on the next game and it's relatively simple to fix, they will (should) just go and fix it up and release the patch then. Hopefully it's one of the first things they work on so it will be found early on in development. Failing this, I can see a large swathe of loyal fans being disgruntled and refusing to buy the next version upon release.
Destiny kind of did this. The base Destiny was pretty rubbish, especially the end-game but as they developed the DLC they released patches to improve the base game. Unfortunately, a lot of the shiny new game improving content was locked behind a pay-wall, meaning you had to buy the DLC to get the most out of it and that p*ssed a lot of people off. While the DLC wasn't necessarily worth it for the content, it was for the total game enhancements. It was a new model for how to maintain and sustain a game 2 years post release (coming up 3 years) which for me, would be a better model for a game like DBC rather than a completely new game every 3 years. Release small/medium DLC enhancements to keep the revenue flowing through the doors while you improve the underlying game engine and mechanics. For example, they replaced the whole voice dialogue because they thought it was bad and re-recorded the whole character and loaded it in to a patch.
By no means am I suggesting a pay to play model, or advocating releasing half baked games and make people pay to get a proper experience. But for arguments sake, release an Ashes 2017 DLC that included all 5 official test venues and 2 licensed teams (never going to happen due to CA and ECB greed, mind you) as an excuse to keep funding the development of a 5th patch with a view to getting some revenue out of it at the end. That way, the game gets enhanced for all, and those keen on the new content will be happy to fork out $10-20. The problem DBC has now is that all this is available through the academy at no charge, so people won't want to pay for something they currently get for free (basic economics). They'd need to think of a different tact for DLC (historical teams/scenarios mode, new commentary, accessories - I know at least one person who would pay a lot to have alice bands in the game, perhaps?).
I think it's almost as if BA's generosity has now limited their potential revenue stream and ability to enhance the game engine further. It may not be popular, but paid DLC is pretty much the sustainable future of video games. I'm happy enough to go with it as long as you cant pay to be successful. If all you're paying for is new stadiums, bats, team kits, etc (a la Forza Racing) that doesn't change the underlying mechanics and balance of a game then I'm ok with that. Once you start paying for better players/enhancements and consumables then the model breaks (think Fifa/GTA V).
