https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3369154/This phenomenon has been reported in the literature as proximal fibular migration (PFM)
And this author says:
PFM induced valgus deformity of the knee, and premature consolidation of the fibula was associated with the distal migration of the proximal fibula.
These mechanical malalignments could sometimes be serious enough to warrant surgical correction.
Thus, during lengthening repeated radiographic examinations of the fibula are necessary to avoid complications.
In this image, it is clearly visible that PMF is occurring. PMF does not heal on its own and requires additional surgery to correct it.
On the other hand, the following article reported that there were no clinical symptoms related to inferior subluxation of the fibula (PFM).
https://pubmed.ncbi.nlm.nih.gov/15252098/It is true that Dr. Yuksel didn't fix the proximal fibula to the tibia, but I'm not sure how much that would hurt the patient.
Top-class doctors almost always perform this fixation, but I think doctors in developing countries often omit it.