Quill owners could prevent that while selling. I'm pretty sure they were aware that Twitter will/could do that.
You can negotiate these things while selling.
You can negotiate these things while selling.
If it’s something the buyer really doesn’t want to do, it would be a lot of money and could kill the deal.
Can you do so in a legally-binding way? Surely if you are selling then they own the company, the staff, etc and can do whatever they want?
To do otherwise would mean that you still retain ownership and control of the company, thus not legally "selling".
For example — it’s not uncommon when adopting a dog to sign a contract agreeing you will walk it N times a week, or never leave it unattended in public, etc.