Generally, that’s what happens. These cutblocks are there because most or all of the trees were of a species that was logged. You might as well plant the same species, because it will eventually end up that way anyway, it just takes longer.

Cutblocks left alone will have some species flourish for a while, but eventually they end up with the species that dominated before by virtue of the soil types and environmental factors. And if you plant that species in parts of the logging area that didn’t support them, they’ll get outcompeted anyway by volunteers of that dominant species.

I’ve backpacked in a lot of virgin and non-virgin country, and the forests that have been logged don’t look much different after 40 years than the ones that have never been logged. Just the size of the dominant species changes.