Hello,
By deregister you mean unregister?
What type of plugins? Built-in or custom?
If it is custom, then the code that has been developped in this plugin won't be triggered anymore, which might lead to loose some functionalities.
If it is built-in, it is not recommended to unregister it.
However, before unregistering any plugin, make sure that this plugin is not used by asking a developer so it will not have impact.
