As you properly note, the rumors flying around have been all over the map. Which will turn out to be true? Your guess is as good as mine. About all that's been confirmed is that there will be a next-gen NSX in another couple of years.
If you're looking for actionable information, I would suggest you only consider that something will be coming along in a couple of years. Don't worry about what it will be. It seems like there is always something newer and faster and better coming along. Unless you know something's coming within the next six months, just keep or buy what you want to have now, and enjoy it in the meantime.