The dev have been really quick to revert the payout from 12h back to 24 hours so I don't see any reasons why it would be different with this change if they notice an negative effect from this change.
I'd say let's see. I agree that 40 is way too much right now. I was able to do 40 semi-meaningful votes per day when steemwatch was up but now I'm not even trying even if I could use other tools to achieve similar results.
Why start with such a drastic change? Why not cut it in half to start and see if there is a positive effect? Deincentivizing engagement on the platform is not a good way to handle bots.
I think too often with steemit the users are tossed out with the bathwater in an effort to curb bots.
Edit: Here is my full post on the 5 votes https://steemit.com/steemit/@contentjunkie/5-votes-is-not-enough