I reckon I'd be safe to assume that 'diabetes' deaths would have been similar last year, and before...and before. If anything, T2D deaths would be well under-reported as it invariably leads into 'Heart Disease' which may not be listed to T2D as "CoD"
I'd query the COVID numbers in the light of what the UK and US governments have been discovered doing... fudging the figures. Blatantly.
For a blunt commentary:-
Lockdown Deaths, Not Covid Deaths
And,
This bloke is a GP who works with more than one Nursing / Care Homes, so he's familiar and up to date with what the NHS is doing...
COVID fear | Dr. Malcolm Kendrick
From memory, he was posing similar questions back in April.
But if you want detail as to how cause of death WAS defined .... before COVID, and now how it has changed -After COVID, go here:-
COVID 19 Is A Statistical Nonsense