There's details in the various resignation letters.
Basically the tl;dr is that the company who owns - i guess - most importantly, the domain (because, what is there even to own in a network where everything's run by volunteers and all the servers are run by sponsors for free?) ended up in the hands of someone who wants to monetize it (sell userdata?) - all of this happened, as i understand, mostly out of control / behind the back of the staff.
In any event, the details don't matter all that much I think, freenode before - libera now; this sort of thing happens from time to time. The positive thing about all this is that it illustrates how resilient irc is to a single corporate entity controlling everything. Sponsors who run servers, can just as easily run their servers connected to a different network. Users with channels can just as easily chat on another network. If anything, the whole ordeal demonstrates how decentralization is nice; if this were discord or slack or something, you'd have to either live with the new management and their policies or have nothing.
That said, the whole ordeal has been somewhat entertaining. It's not every day you see the birth of a new network at this scale. In the beginning there was channels being flooded by botnets, and some ddosing going on- it was like 90's efnet all over again