Do you mean the Chinese government? Be precise, please. If so then I think it's great that they take their miners away. It will level the playing fields for the rest of us who don't have access to dirt cheap miners GPU's and almost free electricity with very cheap rent on storage houses.
51% attack is still pretty cheap if you are first world country. Nice way to destroy currency, isnt it?
Just because you can afford to buy 51% of the bitcoin doesn't mean that 51% of it is for sale. If 50% or more of the holders don't want to sell then you cannot perform the attack. I would say it is safe & if bitcoin could have been destroyed this way it would have a long time ago back when bitcoin was more affordable and there were fewer coins in circulation.