Sky Factory 4 is the same as Sky factory 3. The confusion arises because they played Sky Factory 2.5 as Sky Factory 3. The modpack was 2.5, but the season was 3. they said this at the last episode of season 3.
Then I am really confused for there are other launchers out there that has Sky Factory, Sky Factory 2 and 2.5, Shy Factory 3 and one called Sky Factory 4. I tried theses launchers but can not get a few modes to work so I came the the FTB launcher. So now I am really confused when there is a mod pack called Sky Factory 4 out there if it is actually just Sky Factory 3 with a different name.
Those people are people who are trying to pass off their own modpack as Sky Factory 4, essentially piggyback riding off of Sky Factory's success. The official sky factory 2.5 and 3 is on FTB/Curse. the official Sky Factory 2 is on ATLauncher. I am not aware of where Sky Factory 1 is officially located because I never looked.
Alright. But will there ever be a Sky Factory 4 in the future? It is a good modpack that I like, that is if I can get it to work on this pos laptop more than twice a week :/ Not a good laptop, was a cheepy for my budget so it lags quite a bit or not load at all and that is the normal vanilla minecraft. But ty for your help and I will stop looking for it then.