My guess would be that its just in the news now not that the deaths are outwith the normal range
I think it is more that that we wouldn’t normally expect incidence to rise sharply at this point in the year, and the warnings have gone out in case this is more than just the normal seasonal peak arriving at a different month.
I would expect an increased incidence given that there was very few reported cases during lockdown. It’s not lockdown’s fault, it’s just that these normal childhood infections have been displaced, so more are occurring this year.
Invasive strep A remains rare compared to normal common or garden strep A throat infections. Bit like sepsis is thankfully rare compared to skin infections. Loads and loads of people will have strep throat, very few will go on to develop the invasive, very dangerous version.