No, (a) not all exit nodes and VPN IPs are effected (b) not all servers have that option enabled. I use Tor and am very frequently blocked from using reddit, imgur and other sites because of it.
Honestly the bot detection stuff in production today isn't the most awesome version of that feature possible, and improving it (especially to work with tor and vpns) is a priority, but not the highest. Cloudflare is paying for me to be at DefCon right now to launch an open source firewall / evasion tool (plug able transports to the next level) in 2 days, with the grugq, so it isn't like we are opposed to tor or anything.
