That may be true but can't be read from the quoted reports.
And, we wouldn't expect it to, either. That viruses tend to become less deadly is an
evolutionary phenomenon. It happens over evolutionary timescales - decades, centuries, and millennia. It is not a thing that happens over a year.
That Delta isn't likely to kill the fully vaccinated does not mean it is less lethal.
In fact, as I understand it is not just more contagious (which all by itself leads to more deaths). It actually is more aggressive.
I don't think "aggressive" is a well-defined biological term in this context.
The Delta variant has a higher rate of transmission than previous strains. Preliminary research I've read suggests this is not due to some improvement in spike proteins or the like. Apparently, the Delta variant does this by keeping itself physically the same, but
reproducing more quickly in early parts of the infection. We are all aware that with covid-19, a person can be infectious for a few days before they show symptoms. Apparently, for Delta, the viral load a person can carry in their nasal passages during that asymptomatic period is up to a
thousand times higher than with previous strains. During this early period, when people with Delta talk, sing, cough, or sneeze, the droplets emitted are carrying a much larger dose of virus, making infecting someone else more likely.
This explains why the disease symptoms do not seem to be more deadly, and why the vaccines still work. Delta has changed its reproductive pattern, but not changed much else.