Ok, first, it only applies to Type 2 diabetes.

In a remarkable medical breakthrough, Chinese scientists have successfully cured a patient of type 2 diabetes through an innovative cell therapy approach.

Second, it was done on a case-by-case basis. Each person has their own therapy tailored for them. This does not appear to be a mass-solution.

The groundbreaking treatment involved transplanting lab-grown replicas of the patient’s own insulin-producing islet cells into their body. This ingenious approach effectively restored the patient’s pancreatic islet function, enabling the body to regulate blood sugar levels naturally without external intervention.

From the linked article:

According to a South China Morning Post report, the patient underwent the cell transplant in July 2021.

...

The new therapy involves programming the patient's peripheral blood mononuclear cells, transforming them into "seed cells" to recreate pancreatic islet tissue in an artificial environment. This approach leverages the body's regenerative capabilities, an emerging field known as regenerative medicine.