Good analysis mate. It's still a bit early for me and so the jury is out but you've got to the core of it with this question :-

"Will hf21 see the demise of the bid bots, or will the"War on The Bots" fizzle out..."

I think the vote sellers have too much stake to be losing a flag war, but the old Bid Bot model might now be a bit outdated. Insta-selling is probably the new way to game the system most effectively.