Christel, the previous freenode head of staff, sold freenode to andrew lee (then of PIA). This was downplayed at the time, both publicly and to staff, so this is effectively delayed drama that would have happened in 2017 otherwise.

Christel stepped down, new staff lead shut out Andrew Lee, not realising the depth of his ownership - helped by both Christel and Andrew Lee downplaying it in the past. When it became clear that "Freenode" was owned by Andrew Lee, and not the volunteer run organisation they believed it to be, drama ensued over whether she had the legal right to (probably yes), whether it was morally appropriate to (probably not) and what she actually sold (Freenode runs via volunteer staff on loaned servers, none of which freenode ltd owns or has contracts for, so it basically just owns a domain and a website).

After the legal discussions found that Andrew Lee did legally own whatever freenode itself owned, the staff all quit and formed libera.chat, their own network. Andrew Lee brought in new staff to freenode and some policy changes (notably allowing network ops to reclaim channels that were abandoned as redirects, and toning down the code of conduct portion).

More detailed timeline: https://news.ycombinator.com/item?id=27236455