This makes sense in some ways, but:
What good would it do to have the DNA and no eggs to implant it in? If you stuck the material in a closely related species' egg maybe you'd get a viable gamete. There's been work done on making sperm. But with all rhino species under threat, how long will eggs be available? Or wombs to stick them in?
Where do you put the resurrected species? Global warming and encroachment on preserves isnt' going to get any better.
I'd save that DNA, sure, but don't expect any Jurassic Park action any time soon.