This is very likely the reason this has suddenly appeared in Chrome. Google's revenue relies on ads. Too many internet users blocking too many ads directly threatens Google's revenue stream. The recent sudden upsurge in ad-blocking would, from a Google perspective, look like an existential threat to their very existence.

And what would be one reasonable response that a company reliant on ads for income who also happens to produce a browser used by a huge number of users look like when they realize this existential threat exists? Well, one reasonable response would be exactly this, a "kill the misbehaving ones" addition to that browser in hopes of heading off the threat before it becomes a true, company killing, result.

Only time will tell if this change in mindset on their part actually results in heading off the eventual outcome.