There is the link to this page on this very site regarding relative potential beverage benefits...
Tea is one of the nations favourite drinks and research suggests its also a healthy drink. Tea brings a number of health benefits including improving insulin sensitivity.
www.diabetes.co.uk
Not stating any preferences myself (other than pointing out that coffee is also just as "potentially" beneficial).
Here's a link back to the study:
https://www.acpjournals.org/doi/abs/10.7326/M22-0041?journalCode=aim
It doesn't tell us anything on the other habits of the participants. Was it the tea or can it be that regular tea drinkers statistically make some other life choices as well?
The non tea drinkers must have drank something as well. so what did they drink? Coke and other sugary or artificially sweetened drinks? Beer? Plain water? Can it be that the ones choosing tea, which is generally seen as a pretty healthy drink, made other healthier choices as well?
I think it's pretty important to know what we're comparing, isolating tea and drawing conclusions without anything else taken into account doesn't really sound very scientific, and nothing I've read so far seems to justify the absolute statement that 'drinking Chinese tea is especially beneficial for diabetics'.
I'm not at all saying that tea doesn't help with diabetes, it might wel do. But if someone states this as a fact I'd like to see proof.