It's an absolutely feasible project with a big enough budget. I'm not very familiar with the robotics industry, but I'd be pretty surprised if you can get off the shelf robots to do what you want. If that's true, it would be a pretty massive undertaking to create the bespoke machines and AI necessary for automated reforestation. Even getting to the point of being able to replant in land that is all dirt would take quite a lot of effort, and that is essentially what some agricultural tech companies are doing. But deforested land has all kind of artifacts from what used to be there, that your reforesting machines will have to work their way around. It would take quite an investment to make the leap between what ag tech is doing with pristine fields to what's left behind during deforestation.
For an example, take a look at this image which was the first result in Google images. It's a "cleared" forest in Sumatra, Indonesia.
http://assets.worldwildlife.org/photos/983/images/story_full...