Firstly, please forgive me if there is already a way to do this.
An asset issuer needs the ability to halt trading for their own asset on the A/E in order to fairly account for significant changes to the scope or mission of an asset. A permanent halt to trading is not recommended, only for a few block heights. This will give time for announcements to go out to all stake holders so that they may have a fair chance to adjust their orders on the market. In the long run, this will encourage more people to leave NXT in open orders on the A/E. That is good for everyone in our eco-system because it creates more demand for NXt and more liquidity on the A/e.
Alternatively, a notice response type of special message can be created as an option for asset issuers to notify their stakeholders. The message would have an "acknowledge" checkbox so that the stakeholder can verify to the asset issuer that he has seen the message. Now, if a stakeholder fails to acknowledge after certain block height, then the asset issuer will recieve rights to cancel that stakeholder's open orders.
Perhaps there are other ideas others can think of to accomplish this need: Market makers need fair treatment of the open orders on the A/E when major events occur relative to a particular asset. For example, when one asset is shut down for a rename, or a split, or discontinuance of the project, etc. etc.
If some feel these ideas place too much trust in the asset issuers, then perhaps we can incorporate the voting system as well. We can build a special proxy vote where stakeholders must agree before any elevated privileges are given to the asset issuer. In this case, please be sure to design solution so that all stakeholders are automatically treated fairly, even if they missed the notices affecting their assets.