Do you understand that "reduce" is not synonymous with "eliminate"?
Because an acknowledgement that fully vaccinated people can spread Delta is not a refutation to the claim that it reduces the spread.
Even the paragraph you quoted says "However, like prior variants, the amount of viral genetic material may go down faster in fully vaccinated people when compared to unvaccinated people. This means fully vaccinated people will likely spread the virus for less time than unvaccinated people."
Because an acknowledgement that fully vaccinated people can spread Delta is not a refutation to the claim that it reduces the spread.
Even the paragraph you quoted says "However, like prior variants, the amount of viral genetic material may go down faster in fully vaccinated people when compared to unvaccinated people. This means fully vaccinated people will likely spread the virus for less time than unvaccinated people."