I think the key thing is that it disproves the idea that the bacteria which cause the disease are reliably eliminated by antibiotics, which is typically a key point that those in the "it's not cause by lyme" camp rely on.
Doesn't prove that it is lyme, but it shifts the balance of probablities considerably.
I don't have an opinion on what the "it's not caused by lyme" camp rely on, but the wikipedia page complained about above actually already references another study that found spirochetes in animals after antibiotic treatment.
No doubt the language in that wikipedia page is pretty triggering if you already believe chronic lyme disease is a thing though.
Most CDC / IDSA folks will tell you that a course of antibiotics will rid the body of Lyme in all cases. The presence of spirochetes here should be enough for them to stop using that language. But it likely won't because there appears to be a systemic organizational bias against Lyme as a chronic condition, and I'm not sure why.
Kind of reminds me of Alzheimer's disease and the pervasive insistence that it's cause by misfokded protiens even though so many treatments following that assumption failed to cure it. Sometimes an idea is just hard to introduce or root out in academia