I’m pretty sure you are mistaken on the Israel Delta timeline. Keep in mind, this is an Israeli study on its population so it doesn’t really matter when Delta first appeared in another country.Hmm, I'm finding different media articles saying delta was first seen in Oct 2020 all the way to Feb 2021. I'm looking for a more definitive source.
https://www.reuters.com/world/middle-east/israels-covid-19-vaccine-boosters-show-signs-taming-delta-2021-08-24/