No, a similarity between SARS-CoV-2 and other coronaviruses was expected but not this. Flu is not caused by a coronavirus. From the paper:
> This finding is in contrast to multiple published studies in which pre-existing T-cell immunity is suggested to arise from shared epitopes between SARS-CoV-2 and other common cold-causing coronaviruses. However, our findings suggest that SARS-CoV-2 reactive T-cells are likely to be present in many individuals because of prior exposure to flu and CMV viruses.
I'm not sure about the accuracy of this quote. In git world branch names have nothing to do with repositories. If anything, the "source of truth" repository is generally called "origin".
> This finding is in contrast to multiple published studies in which pre-existing T-cell immunity is suggested to arise from shared epitopes between SARS-CoV-2 and other common cold-causing coronaviruses. However, our findings suggest that SARS-CoV-2 reactive T-cells are likely to be present in many individuals because of prior exposure to flu and CMV viruses.