How will the bowling ball industry be able to meet the new USBC standards for equipment?  I haven't seen a bowling ball with more than three ounces of top weight for years. 

A 3 oz top will roughly be 0 top after drilling keeping the cg near center. Unless you really screw up or get a ball with a very high top weight it should be difficult to drill a ball that won't pass the new requirements of 3 oz (max limit) for all weightings (top, finger, side)

A better question should have been. Will the bowling ball industry provide equipment with enough top weight to be able to support a top weight of 3 ounces?

The bowling industry doesn't have to change anything. With the new rule you should see fewer xouts because of the cg out of line or too much top weight. It gives more room for error.

Maybe you are interrupting the rule differently then everyone else.

When a ball is made; the core is put into a mold that the resin is poured in to.  As the resin hardens; the core from ball to ball settles differently.  One ball, the core could settle slightly more towards the top of the ball creating a higher top weight and another ball the core could settle a little lower or towards the bottom creating a lower top weight. 

Ball companies dont set up the manufacturing process to produce balls with specific top weights.  Likewise for pin distances.  Ball specs are all about how the cores and covers cure together during the process. 

If you are curious as to how this is done, I have included a video as to how balls are made from start to finish from the manufacturer.

https://www.youtube.com/watch?v=YAOX1ekylnQ