So EmuNAND was announced initially for Atmosphere, but we would have to wait for Atmosphere to be completed before we got our hands on EmuNAND. This is being done by Team ReSwitched but judging by the commits, its 99% being handled by SciresM and TuxSH (prominent 3DS hackers). Then very recently, another prominent hacker by the name of naehrwert announced to be working on EmuNAND support. He did not give an announcement date but effectively there were 2 different teams developing EmuNAND. However, when "backup swapping" began spreading, people inappropriately titled the process "Hekate backup launching" (Hekate is just the name of the payload, its the WIP Atmosphere CFW that enables this). Due to not wanting his work being associated with piracy, he did not leave the scene but rather made his work closed-source. So he is still developing whatever he is developing but in secret now. However, we cannot confirm if naehrwert is still working on EmuNAND or not. However, since Atmosphere is still being worked on, EmuNAND is still being worked on there.
EDIT: I need to work on my repetition. Take a shot for how many times I said "however"