Sure, we’ve sequenced the genome, but they’ve tried somatic cell nuclear transfer only to find out that the cell dies with the mammoth nucleus. Unless it was stored in cryogenic storage beneath lead shielding to protect from ionizing background radiation it’ll never work.
The only hope they have is cloning huge sections of the mammoth genome into the elephant genome, which is a project the size and scale of which will never be performed if we can’t even be fucked to properly care for their only surviving relative the elephants (or even care enough to do anything about global warming for that matter).