The point is that any insurance company asked to provide a policy for table saws would mandate this technology for any saws it covers. Same way we got UL (underwriters laboratories!) listed electrical equipment.

To state the obvious, a consolation prize to someone who loses a finger isn't the point. Rather the purpose of said proposed legislation would be to incentivise rational economic actors to purchase safer machines. Assuming the premium discounts were greater than the added cost of the "safe stop" technology amortized over the lifespan of the machine, they would. Either that or go out of business, further automate production, move shop to Mexico, etc.

insurance offers discount for car alarms and lo jack, and that drives purchase of those items.

It's both. Having to pay increased premiums if you put someone in danger means your more likely to buy safer tools in the first place.