As I understand, it is hovercard's policy to remove bracketed content in link previews (which is a good thing). Well, it is failing to do this when the IPA template is used within brackets. It seems to end the omission at the end of the IPA template rather than at the closed brackets. As you can see in the example below, it correctly omits the next set of bracketed content after the first failed omission.
Example: page – link preview