From the article: "Tech companies should include mechanisms in the design of their encrypted products and services whereby governments, acting with appropriate legal authority, can obtain access to data in a readable and useable format"
They would target companies, not math or protocols.
But software is written not only by companies. Single person can deliver to millions of users and remain anonymous if he's careful.
So drop the idea you can prevent encryption, learn to live with it. Drop the idea of giving your policemen ability to time travel and listen to anyones private conversation from the past while remaining invisible. It would be nice for you but physics (of internet) does not allow it.
They would target companies, not math or protocols.