[1] https://en.wikipedia.org/wiki/Chernobyl_Exclusion_Zone#Curre...
My comments are based upon observations of several years of visiting, and speaking with scores of people that work/live in the Exclusion Zone. Anecdotally, large Animal sightings of things like Moose are rare enough that even people who have visited hundreds of times, over decades, will stop, get very excited, take photos, and then chat about the last time it happened.
Edit: this report agrees with what I have found (in real life)
https://academic.oup.com/jhered/article/105/5/704/2961808
"All major taxonomic groups investigated (i.e., birds, bees, butterflies, grasshoppers, dragonflies, spiders, mammals) displayed reduced population sizes in highly radioactive parts of the Chernobyl Exclusion Zone."
Isn't this what should be expected? Even in ordinary wilderness like Maine or Canada where moose are indigenous, you could spend a year in the woods and never see one.
To give this more perspective:
For the last several years, I have spent many months each year in the Chernobyl Exclusion Zone. Most of that time is not in Pripyat, or at the extant plants being decommissioned, it's in the nature areas throughout the zone.
My observations: birds are rare. I've seen an eagle once, and some other smaller birds occasionally. In Pripyat, I've never seen a bird. Insects are also rare - I once saw a swarm of flies inside a building at the Duga Radar facility, but never any bees, cockroaches, or other insects. Not even mosquitoes. I've seen moose, once. Horses several times (Mongolian horses been introduced to the area post-disaster). There are foxes, but they're often the same foxes I see time and time again. Dogs are probably the most common animal, I would estimate I've seen 30 - 50 different dogs, always hanging around where humans are. The catfish in the cooling pond canals are enormous, and plentiful.
Although parts of the Exclusion Zone are exceptionally green, such as Pripyat itself, much of the zone has a feeling of unhealthiness. Infamous areas such as the Red Forest remain too high in radiation to spend any amount of time in. The areas around the cooling ponds (which are large enough to appear like lakes) look like what you imagine an environmental catastrophe would look like - grey and barren.
I see more wildlife in any major city - and would be reluctant (and that's an understatement) to call wildlife "thriving".
Aside:
As you point out, human lives lost were relatively few. However, this place will be an ongoing disaster for many thousands of years to come. There will be ongoing huge expenses (the most recently installed containment structure will only last another century). Reactor four needs to be contained for thousands of years, and the other reactors will require another sixty years to be decommissioned.
And after all that, the main danger, deep inside the debris of reactor four, will remain an enormous danger to the planet for any foreseeable future.
In general, the radiation levels throughout the Exclusion Zone are low, comparable to many cities. I have many scheduled visits upcoming, the next being in August.
BTW, I'm not taking a stance here on pro or anti-nuclear, just trying to add some context from someone who has seen this place, up close, many times.