Does not necessarily "kill the market", as the large sales will be through platforms subject to tax laws and combating money laundering and thus give a kind of legitimacy and distance from the link between bitcoin and dark activities.
It all depends on how the market evolves. The largest sales happen through OTC markets already, which is done to avoid being subject to every twisted form of regulations, and to avoid being subject to incompetence of the current exchanges. If nothing changes in that regard, and right now there definitely isn't anything going to change, it will only make sure the OTC market grows even larger.
By volume the OTC market is easily somewhere in the range of 10 times larger than all the on-exchange volume activities, but we unfortunately still depend on crippled exchanges to set the price. If we look at the markets as a whole, you can clearly see how exchange volumes have gone down consistently and OTC volumes have gone up consistently. The shift is massive and can't be discarded.