Last I heard they want to switch to another platform, and don’t consider it worth upgrading to 0.19 because they’re leaving soon so it wouldn’t be worth the hassle.
This is pure guesswork on my part, but they could be waiting for Sublinks (a Lemmy-compatible backend) to get up to speed before switching to that. They say that the new platform is “compatible with all Lemmy apps”, and Sublinks is the only project I know of that fits that criteria.
The first part of the joke is that the image shows “Mitosis” - a process in which a cell splits in two. The word sounds like “my toe, sis”.
The second part of the joke is that the Mitosis diagram vaguely resembles “Loss”, a webcomic. https://amp.knowyourmeme.com/memes/loss