Monoculture=bad isn’t really new. It’s been obvious for a long time.
There are some semi-wetlands around the college I attended. They are “untouched study areas” after being leveled for one reason or another. Some of them they planted with a variety of native flora, some of it was left to do its own thing, some of it was left but managed.
The intentionally seeded areas with a diversity of species recovered the most fully (to date - 40+ year project) and the fastest. They spread into the rest and helped reclaim it as well, quite quickly. However, all of the land went through several stages where it looked like it was failing, and it’s actually really important to just let that happen, it’s part of the cycle that doesn’t get to happen in managed forest land.