I hope so too! I'm self-hosting Calckey via docker right now, and having one ready-to-go docker was something I found quite nice with Calckey. I hope this continues to be the case with Firefish
Calckey is a Misskey (https://misskey.io/) fork, hence the name. Misskey is an extremely popular fediverse microblogging service from Japan with a lot of functionalities that Mastodon doesn't have (quote toot, emoji react, ...), in fact if you follow any Japanese accounts on Mastodon there is a good chance they are using Misskey instead
Basically Calckey diverged enough from Misskey (and I suspect Kainoa didn't like the name) that they agreed to rebrand. Kind of a big deal tbh