Yeah I don't know
What is this checkmate called?
According to the Chessable Checkmate course, this is a "triangle mate" as the queen, king and rook form a triangle.
Does every checkmate have a name?
I don´t know. The following checkmates are in the checkmate patterns manual:
Anastasia's mate, Greco's mate, Arabian mate, Hook mate, Vuković's mate, Smothered mate, Suffocation mate, Corner mate, Morphy's mate, Pillsbury's mate, Opera mate, Mayet's mate, Lolli's mate, Damiano's mate, Max Lange's mate, Dovetail mate, Cozio's mate, Swallow's tail mate, Guéridon mate, David & Goliath mate, Boden's mate, Balestra mate, Double knights mate, Double bishops mate, Blackburne's mate, Blind swine mate, Epaulette mate, Back rank mate, Lawnmower mate, Triangle mate, Kill box mate.
Some of these mate´s are known by other names (such as The Kiss of Death as someone mentioned earlier).

According to the Chessable Checkmate course, this is a "triangle mate" as the queen, king and rook form a triangle.
Thank you so much!
This is a kill box mate.
Kill Box mate:
Triangle mate:
Very slighty different but essentially the same.
It seems a little different than a regular dovetail though