Scientists say they are close to resurrecting a lost species. Is the age of de-extinction upon us?

Betteridge's law.
In this case, while it might be possible to reproduce a member of an extinct species, if the conditions which cause the die-off of that species are unchanged then the species will still be extinct. The living individual would be a curiosity at best.
- Not only that but would so few specimens be a minimum viable population? This would be a pretty large number of individuals to attempt true rewilding.

Where are these mammoths meant to roam ? And does anybody get why they think trampling grass and snow is going to protect permafrost ?
- Great question! Thankfully somebody is already working on that, and it's pretty neat.
  https://wikipedia.org/wiki/Pleistocene_Park
  
  OK so I read "Here the key concept is that some of the effects of the large herbivores, such as eradicating trees and shrubs or trampling snow, will result in a stronger cooling of the ground in the winter, leading to less thawing of permafrost during summer and thereby less emission of greenhouse gases".
  I know the big impact of trees and shrubs on albedo - in spring they absorb sunlight and shake off snow, which remains on flat grassland. But regarding trampling - compaction- I'm not convinced. Winters are long and summers short, so accelerating cooling by some weeks wouldn't make so much difference, as accelerating warming in the summer - that's when the gases are released.
  Anyway what we do urgently need is global science cooperation to try to save the carbon and ecosystems of that permafrost, in that spirit such projects might help to thaw geopolitical obstacles.
- Not to mention rejection/loss of their mothers.
  So here are some hybrid elephant/mammoths (because take modern elephant egg and replace parts if it with edited dna, keeping most of the modern cell) ; who probably will experience constant pain and unhealthy feelings due to the editing; having life long psychological issues - with no real place to live except in a nature preserve.
  The first viable generation will probably be so messed up they need humans to raise the second generation; and the future generations will probably not feel healthy.
  Has anyone ever had to deal with several tons of grumpy issues ? I’m fist it’s not me helping
  This is why I totally do not support such efforts, done for things other than the new life’s value

My problem with private companies doing this, is that, it will probably end up like the cryogenic fad.

Did those scientists never read jurassic park?
Not that bringing back the dodo bird or mammoths would have quite the same effect probably but species go extinct for a reason.
- In a lot of cases, the reason is that they were driven to extinction by humans.

I guess the reasoning behind this is to foster the abilities in genetic engineering.

There's some poetic justice waiting to happen here.

I understand the Dodo and Thylacine—colonialism has been a disaster for ecosystems around the world and restoration is very much desirable—but why the woolly mammoth? What possible benefit could come from destroying the ecosystems we've had for millennia to replace them with a facsimile of the ice age?