Is there a way to hide Matrix blocks based on the Selected Entry Type?
No. Matrix blocks do not work in that manner. However you define it in the field is how it'll show when you edit it. If it's really important not to show that block type you can write a plugin that checks for an entry type, and hide certain block types based on that result. Granted that's a lot of work for very little gain. You would be better off ignoring the unwanted block types or building a new matrix field.