medborgare

Is “switches” really correct? They’ve been on Mastodon since 2017.

Could they still keep the content but not have it available to the public until it enters public domain or copyright laws are improved?

Are there any similar communities on Lemmy?

I don’t think any of these statements are true, I particular the “failure” and import needs you mention. Sweden has been a net exporter for most of the past years and 2022 they exported most energy of everyone in the EU: Sweden remains Europe’s largest net power exporter.

And the current Swedish government are absolutely talking about new reactors:

Finance Minister Elisabeth Svantesson (M) and the Minister for Civil Defence, Carl-Oskar Bohlin (M), promise that new nuclear power will begin to be built in Sweden before 2026.

Source: Ministrar: Påbörjar ny kärnkraft före 2026.

They also seem to be abandoning their previously communicated plans of opening old ones:

The Tidö agreement promises an investigation to review the possibilities for restarting the Ringhals 1 and 2 reactors.

But an internal memorandum written by SD's top official in the steering group for Vattenfall testifies that KD refuses.

SD can drop the demand to restart one reactor - the party leadership is now being asked to act to save the other.

Source: Tidö-partier i strid om Ringhals – Ebba Busch vägrar återstart (KD and Busch holds the Minister of Energy, Business, and Industry position)

Exactly, defederation is just a tool and it’s up to the owners to use it when appropriate and in line with their goals for the instance.

For example when brigading happened on Reddit some subreddits had to go private to defend themselves, with Lemmy the owners can defederate from the offending instance instead but still keep access open for everyone else. Another aspect is the legal side, as someone else also mentioned the content OP talks about is illegal in many countries and due to the way the Fediverse works owners of the federated instances will end up linking and hosting that illegal content on their own servers as well, unless they defederate.

I think their problem is open enrollment in combination with lack of moderation and mod tools to handle that. Defederation is not permanent, as Lemmy implements better mod and admin tools instances which have defederated to mitigate spam or trolls can start opening up more again.