I appreciate your paranoid-by-default stance on things (It’s good to be a skeptic) but in this case, the likely answer is someone was banned from that IP (likely, someone was banned then tried to use a VPN to get around the ban, thereby causing all those users to be banned as well).
Spammers also love to use those VPNs to spam from, so it’s also possible Akismet banned that IP as well.
There’s no “policy” being pushed by anyone, other than the community guidelines pointing out that 1) thou shalt not spam and 2) thou shalt not attempt ban evasion by using other IPs.
