All by the end of March.
The Ketchup v Mayo re-run in Splatoon 2 was popular enough that the repeats will continue.
Nintendo have announced three more Splatfest reruns will occur in Splatoon 2 between now and the end of March 2021. The first, a rerun of the "Chicken v Egg" fest from March 2018, will run from 6 p.m. ET on August 21 to the same time on August 23.
The identities of the other two Splatfests have yet to be announced.
