I disagree with this personally. I think he had abandoned it and has zero intentions on ever finishing it.
What actions has he shown to think his still actually working on it? Words? Words aren't actions, they're just words. The last time he showed something it was a random Day 4 script from what I can remember - hardly proof of anything. He hasn't shown anything since then and I even offered to look over what his done but he also didn't respond to any part of my message after he finally contacted me -
not a word.
It's been how many years since he started this merge thing and it still hasn't gotten done? Coders abandoning it or not - BlueCat himself as abandoned the game. I did it in a month, those same "problems" he mentioned about coders having different styles - That didn't stop me and I knew nothing about renpy's coding or anything.
In fact, I merged the game twice, from scratch both times (I didn't have the first merge files anymore and had completely forgotten stuff I did

) but the second time was way better than the first since I changed a lot of shit around to make it more consistent and actually tried fixing the features on the second go around which I didn't do the first time.
Point is, it should be done. There is no logical, sensible reason or excuse a human being could come up with let alone BlueCat to explain why it hasn't gotten done after all these years. I would say prove me wrong, but it's been years - we've all been proven right.
It should be done. It's not. It's never getting done. It's abandoned.
(P.S I still like the game though, obviously)