The new organization is at https://github.com/FossifyX. For now all the apps have updates disabled, i'm quite open to alternatives for all EXCEPT Gallery, so i hope the fork goes well, at least from the discussions it looks like it's off to a decent start.
Of note, the apps on FDroid are still uncrapped so you can still take them from there.
I don't even use SM apps (I've tried a few and they're great for simple, straightforward, no-BS, functional apps), and I'm very glad to hear there's already a fork.
So this just looks like the Community has to take care of the projects and/or find alternatives
Alternatives
File manager - Material Files
That one doesnt have the security vulnerability and I think it is also better. But they are pretty much equal.
Simple Gallery - Aves
I prefer Simple Gallery though, it is pretty great
Simple dialer - Welefon
Very basic, I personally use ACR phone for call recording, with disabled internet permissions. The Dev asked on Reddit about opensourcing the App and got negative responses, so maybe unlikely.
Simple Keyboard - Florisboard
Currently unmaintained but awesome. I hope it gets revived.
The interface looks nice but I'm not too keen on the network and location permissions. I really liked Simple Gallery for just a "show my folders" view.
Lucky you - you have the latest and greatest of these specific apps. Now, depending on how you installed them, go ahead and disable any automatic updating.
Then, just keep an eye on the forked versions in Github, which were created by another dev who worked very closely on the Simple Mobile Tools.
Eventually there'll be new releases that you can install via Obtainium or F-droid. All the main SMT apps had settings export/import capability, so I imagine you'll be able to bring your settings across to the forked versions too.
Bit of short term pain to change over, but not all is lost.
I love it. Used it for years. But it really hasn't worked properly for the past maybe three years now. Read some of the reviews on Google Play. The F-Droid version misbehaves the same way. I've considered forking and working on it myself, but I don't know enough.