It makes sense. You want to make sure that the person A has a vested interest in making sure that people will stick around. Certainly not to encourage them to leave (or assist them or make it easy for them to leave after getting the money).
As a contract term it's legal just like if you are selling a ski resort you could say "if it doesn't snow 30 inches next season then we want ..."
Making something a term doesn't imply that you have control over the even directly necessarily.
For example let's hypothetically say that PG decides to sell HN. The terms might be that at least 70% of the top people who comment stick around for at least 6 months. So if PG had knowledge that those top people who comment would leave if he sold then he would have to factor that into the price he is being offered. And if he ran into them at a party he wouldn't be egging them on "oh now that I'm not affiliated I don't really care what you do".
First HN commentators are not employees or workers in the legal sense.
But the employee now works for the acquiring company B how is it legal that the stake holders in company A can be penalized after the fact for the acquired employee deciding that he doesn't like the new employer.
Oh I know that trust me I do but we dont in normal legal system punish people for the actions of others (not with standing conspiracy which is bloody hard to prove)
This system lends it's self to blackmail "hey ex boss give me 50% of that hold back money you got from the acquisition or I will leave and f&*k you over".
ps Yes I am aware of the "joint enterprise" issue in UK employment law where you can legally fire all of a group of employees if you can prove that one of them did something realy naughty.
It doesn't preclude a similar retention bonus for the chef. The point is, the leadership of the selling firm has some influence over whether their employees stay or go. The buying firm sets up a financial incentive to encourage the selling leadership to use that influence.
As a contract term it's legal just like if you are selling a ski resort you could say "if it doesn't snow 30 inches next season then we want ..."
Making something a term doesn't imply that you have control over the even directly necessarily.
For example let's hypothetically say that PG decides to sell HN. The terms might be that at least 70% of the top people who comment stick around for at least 6 months. So if PG had knowledge that those top people who comment would leave if he sold then he would have to factor that into the price he is being offered. And if he ran into them at a party he wouldn't be egging them on "oh now that I'm not affiliated I don't really care what you do".