This one is really difficult, because with AL he wanted to shock, to get people talking and to generate interest and he succeeded.
Now with BaD, above all, he wants it to be remembered, and he will not taint his "masterpiece", like let's say Bioware did with Mass Effect, which had people going nuts and "forcing" Bioware to create a new ending.
Most college relationships don't make it all the way, so one has to always keep that in the back of ones mind, but if we ignore that for a moment, some paths certainly offer the prospect of what most would consider a "happy ending".
I think he will cover the whole range, like some stories for example Jill's, is already being setup for it so smoothly. Jill never gets tired of telling the MC that money doesn't matter to her, or that her expensive car or furniture doesn't matter to her. I can easily see - if their socioeconomic differences cause a divide between Jill and her family - that she just says "I made my choice" and then rides of into the sunset with the MC.
Also Sage's, Bella's and Zoey's story could very well lend itself to a happy ending. DPC is not going to let problems that he already dealt with reoccur, like the MC and Bella, 1 year later suddenly getting into a conflict over stuff like "Oh shit, you're 20 years older than me."
Then there are the obvious ones who lend themselves far better to not so happy endings, with Quinn being the groups frontrunner.
BaD also has one huge advantage, it only covers the MC's first year in college, so it's super easy to create happy endings, because nobody expects an ending that covers the next 50 years.
I'm 100% certain, that DPC will do BaD and the paths he created justice, so Episode 16, unless he uses 2 Episodes to cover all the endings, will have a development time of 2 years+ with 12.000-15.000 renders to leave one final statement and "never been done before" moment, no way he is gonna pass that one up.
Let's hope we are still around for it my friend, just imagine, an Episode where you can make an entire run of the mill F95 game just by using all the previews released during it's development.