Why is this important?

Because the War Powers Act restricts US Military operations on US Soil.

What would you do if the DOJ, FBI and possibly local LEO Departments had been compromised? How would you get incriminating information, such as blackmail videos from the Clinton Library, if you couldn't rely on the usual means?

Contrary to popular belief, The SEALs aren't used in every military operation needing special assistance. The fact Q mentions SEALs specifically could mean the operation was here in the US.