Just one man's opinion, but the requirements have already been widely agreed to. Doubling cage space, etc. The main point of this bill, which hasn't even been written yet, is to level the playing field for all producers. In other words, rather than have this agreement with some, but not all, producers, those who agree would be at cost of production disadvantage to competitors who did not voluntarily agree to the changes. By codifying the agreement, all producers would have to abide by the proposed changes.
The time frame suggested is something like 16 years for full implementation. This long time period allows producers the time to make the change over within a normal depreciated period, for the equipment involved. There is also political pressures from foreign governments to level the playing field internationally so that no major egg producing country has a perceived unfair advantage in cost of production. The UK and the EU are already dealing with this issue and implementation plans are in process.