"new" == ~3 years old (but looking to move from alpha to beta in 2024 IIRC). It's a good server!
That's not what the story is here - this is an additional fund raising entity to support the independence of the platform. The post is very clear that Mastodon (the project) remains a European organisation
However, it’s also important for us that Mastodon is one of the few, if not the only social media platform that operates out of the EU, and we would like to keep it that way.
Sounds like a plan.
I think forcing all posts to be opted-in to the search, and depending on users to opt-out, would be far more controversial? Either way, the user does get to control this within the platform.
I wrote a blog post about using Postmarks and contributing to the project https://andypiper.co.uk/2023/09/11/bookmarks-in-the-fediverse/
At the moment it is explicitly designed as a single-user implementation, although I'm sure it could be pivoted to become multiuser. I've simply set up my own on Glitch and it is working great! -> https://pipesmarks.glitch.me/
For what platform?
I do not know if it is on the Fedora roadmap, but I can recommend taking a listen to the most recent episode of Linux Matters, where the three hosts talked a lot about backup strategies, and also mentioned GUIs.
I wrote about this on my blog. I like the notion and points made here, but I also think we're not helping by re-inventing things that already exist, so I'm torn on it. I have been happy with the existing one.