Radiofrequency ablation (RFA) is a minimally invasive procedure for treating benign thyroid nodules that present with clinical symptoms. However, the tissue alterations induced by this procedure can modify the sonographic appearance of a nodule post-treatment, causing it to resemble features suggestive of malignancy found in untreated nodules. This critical narrative review examines the limitations of applying the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) following RFA. It addresses shifts in sonographic features, an escalation in risk stratification, the persistence of viable tissue, nodule regrowth, and the diagnostic challenges arising from these changes. Findings from two observational studies that specifically investigated changes in risk stratification following RFA indicate that, despite a significant reduction in nodule volume, the sonographic features may shift toward categories associated with a higher suspicion of malignancy. In one of these studies, the proportion of nodules classified as TR4 or TR5 increased from 40.1% to 70.1%, while in the other, the mean TI-RADS category score rose from 3.04 to 4.25. These changes were primarily characterized by decreased echogenicity and the emergence of echogenic foci, whereas alterations in nodule margins and shape were observed less frequently. However, an increase in the TI-RADS category does not necessarily imply a higher actual risk of malignancy; it cannot be equated to a histologically confirmed diagnosis of malignancy, nor can it serve as a basis for determining the false-positive rate. Pathological studies have shown that changes such as necrosis, hyalinization, inflammation, and fibrosis occur within the nodule tissue following radiofrequency ablation (RFA); however, the specific, direct correlation between each of these changes and sonographic findings has not yet been definitively established. Furthermore, research investigating the volume of residual viable tissue, Doppler ultrasound, and contrast-enhanced ultrasound has primarily focused on predicting nodule regrowth or the need for retreatment, rather than providing direct evidence regarding the diagnosis of malignancy. Consequently, the interpretation of sonographic findings post-RFA must account for several factors: the level of confidence regarding the benign nature of the nodule prior to treatment, details concerning the ablation procedure, the evolution of sonographic features during serial follow-ups, the location of any residual viable tissue, the vascularity status, and the patient's clinical course. Ultimately, to validate the applicability of the standard ACR TI-RADS criteria for assessing thyroid nodules following ablation, prospective, multicenter studies are required—incorporating standardized imaging protocols, independent reviewers, appropriate diagnostic reference standards, and long-term follow-up.