To be honest, any time someone tells you that something is 'good for "diabetics"', you can switch off and ignore them unless it's prescription medication. The things that are 'good' for people with diabetes are exactly the same things as what is 'good' for anyone else - the only difference between people with diabetes and people without is that the people with it need to manually manage their blood sugar.
Cinnamon is believed to help reduce blood sugar levels in people with T2 diabetes but as far as I know there has never been a study done into it, nor is there any evidence to suggest this happens other than the odd anecdote. I certainly wouldn't advocate spending money on special pills given that cinnamon is available very cheap as, well, cinnamon and could be easily added to foods if you really want to try it.
Next time anyone tells you something is 'good for "diabetics"', ask them to justify why. If they can't give you a straight answer, ignore them. If they say "it's good for blood sugar", ask them "how?", and if they ever say anything involving the phrase "at the cellular level", ask them what their sales commission is.