Comment by waserwill

My guess: if non-genetic heritable elements -- epigenetics (such as modifications to DNA) -- are necessary for proper development, then the DNA sequence alone will not be enough to develop thylacines. (There are caveats, notably that some modifications can be inferred). However, the scientists will also be experimenting with gestation and creating embryos from modified cells, so whether epigenetics specifically is a limiting factor will be hard to tell.