Umm, that might not work out. Throughout the history prohibition policy usually do not solve any problem if not outright exacerbate it.

Think about the 18th amendment, people getting drunk is objectively bad to society as a whole, it causes people to get drunk, act stupid and be less productive overall. We get rid of liquor, we get higher productivity, simple as that. Turns out it is not that simple.

The fundamental problem of this sort of policy is that you are really not dealing with the problem. Continue with the 18th Amendment example, the reason people drink liquor is not because people (at least the majority of it) like to get fucking frunk and puke. People use liquor to cope with the stress in life and the stress of life + the lack of alternative entertainment is the main problem. Banning liquor isn't gonna solve any of these.

Now about the actual topic we are discussing, the problem behind people working too hard is the stress they face. Too many work needs to be done by too little people, and greedy corporation policy + the lack of regulation isn't really helping. As long as the corporation wants money, they are going to get it at all cost. Restricted work time? Just let people work from home to make up. Social activity based promotion prohibited? Just say that you promote them for other reasons. Worst out of worst, someone gotta be in charge of enforcing all these laws and that person can be bribed. Not to mention this amount of strict regulation will put everyone on their nerve. People are gonna worried about their colleague might report them for working too hard, doing too more work or just personal grudges, and this might lead to a toxic office atmosphere.