I said it in BA's thread and I'll say it here: it's the internet, everything gets leaked. If I made a visual novel about Cthulhu taking Lovecraft on a romantic date to the tentacle beach only for them to end up going on an epic (and naughty) quest to cure a global pandemic, I'm sure that would be leaked too if I ever shared it with anyone at all.
Do I agree with it? Not at all, no. Not in this specific case where the game in question is updated weekly with a couple minutes of content and you only have to wait for literally 2 days for a proper public release (which would hopefully have a few bugs squashed by then).
That said, a dev/artist/producer/whatever being afraid of anything they make being leaked on the internet (in 2020 of all years) is like someone being afraid of getting wet for standing out in the pouring rain. Protest and yell all you want, it's gonna happen.
I'm not saying they have to like it or embrace it, I'm saying it's inevitable. Even if BA's dev had abandoned F95 and continued development of the game, it would still get leaked, with or without his presence. That's just the nature of the beast.