No, that’s not true. Rapid change is possible. Majority of world is only 7 connections part, given enough social pressure, it will stop. Having simple messaging is critical, such as if you eat meat, not talking to you, buying from you, voting for you, etc.
One thing that would be useful though is a super cheap test to check if someone has eaten meat recently.
Best to just shoot these pesky meat eaters in the name of saving the planet, right? /s
Think it’s much more likely meat eaters would be the ones doing the killing.