At the time, little was known about this new variant except that it was extremely different from all that we had seen before, which would very likely result in escape from prior immunity, and may even lead to more severe disease (or not?). The only definitive silver lining that she found at the time was that 1) the variant could be quickly detected with PCR thanks to its S-gene deletion, 2) it was detected early thanks to South Africa, and 3) vaccines could be quickly adapted if necessary, thanks to mRNA vaccine technology. However, in all other regards, the variant was still very concerning.
In other words, do take her cautious optimism seriously. She's not a wishful thinker. Rather, she is a specialist in the field who works with the data as it becomes available and knows how to interpret it