I'm not a lawyer, this is not a legal advice site. Opinions, here, are just that: opinions. To have a definitive answer, you should consult a lawyer.
I know that under parody law [...]
I would suggest to be cautious about it. To use that it's easier if you have an history of goofing around with various subjects. Microcraft could very well be interpreted as defamatory by Microsoft. Since they have more money than you do, they'll be able to make their case clear to a judge more easily than you will.
But what if I provide users an Editor where they can change company name [...]
It depends.
If your game is to be played in a single player fashion, and that this name will never be sent out in the public, nor shared, you won't have any issues.
However, if you're to publish content on the internet or to other users, this could become an issue. You will not have to enforce Copyright police until BigCompany thinks it's too much. You might want to consider to putputting a mechanism in your game to prevent the usage of certain names.
so no one can really predict what next name could be
If your game generates the name, and a company think a name generated by your game violates their trademark or their copyright, they'll blame you and a "not my fault, it's random" defense will fall flat. Again, you'll have to add a way to prevent some names from being generated.
I'll say it again: you should consult a lawyer, before you release your game.