The UK conclusion is strange. The evidence from other countries around the world (not just the US CDC) suggests it's type 2 that's the highest risk. If covid's a vascular disease, which seems likely, that makes sense.
It really is not strange at all.
Type 1 compromises vascular health. Microvascular changes can be ticking away in the background for years, not really causing any trouble unless an extra variable (such as covid) comes into play.
After 10 years, most people (including children and teens) will have a degree of background retinopathy (slight changes at the back of the eye) visible at their yearly eye screening. This is not a problem at all in and of itself, it's just what happens with duration of disease.
We are now beginning to realise though that there are frequent correlations with similar amounts of microvascular changes in the kidneys, and the heart. So much so that there are studies to see if people at risk for cardiovascular disease can be caught at a very early stage (giving better chances of good outcomes) via eye appointments in future.
Anyway - the point of that is that all diabetics are vulnerable to vascular disease. We still do not know enough about what exactly covid does to the vascular system, but reading the accounts of people experiencing chest pain or needing blood thinners months after having covid - people with diabetes need to be cautious.
Dying isn't the only bad outcome here. As a T1D I don't want to put my already compromised vascular system under more strain from a virus that is causing not insignificant vascular problems in healthy, fit people.