Nah, you're misunderstanding. The FISA court is only for formal intelligence filings which could be used for active casework.
Assuming they play by the rules (they don't, but anyway...) all they'd have to do to get your emails anyway is ask GCHQ for them. GCHQ isn't American, so they didn't break any laws by grabbing the content and metadata for all your communications. GCHQ passes the data to the NSA, and boom, they have your data. Legally, with no FISA warrant.
The FISA court is a rubber stamp, anyway-- look at their approval rate.