I am certainly not defending the actions. I just know that that 720 number was found by searching netsplit.de's list of Freenode channels for "libera". It is not a list generated from known takeovers. And I know that Andrew Lee created a new set of rules (after the fact) for this act which center around primary channels (single #) as a cover for his (still obvious) bad behavior.
So, definitely not in defense, just pointing out where the numbers came from. The ##* channel I've op'd for many years with hundreds of users has had "libera" in the topic for a while and has not yet been taken over. But we are moving regardless.
The new policy says "Primary channels are required to stay open. If a primary channel closes access to its users or is in violation of freenode policies, then it will be closed and forwarded to a topical channel."
So I assume that advertising Libera is not (yet) enough to be taken over. Taking over channels that declare themselves closed (and redirecting them to an unofficial channel about the same topic) seems reasonable, tbh.
Channels that hadn't even moved were taken over, such as #elixir-lang. They only had a mention "Also see <channel> on <network-that-shan't-be-named>" in the topic. Well, they have moved now.