I mean---maybe? That wouldn't necessarily be malicious, but I think it's fair and appropriate to apply a healthy amount of skepticism and suspicion to their purported goals and reasoning. Beehaw is a self-proclaimed "safe space", and unfortunately that term has become a kind of dog whistle for militant identity politics.
Particularly in instances, like this one, when thinly veiled patronizing is wielded to preemptively paint a large group of strangers with a very broad brush in the purported aim of protecting marginalized persons from "malicious" outsiders, my cynicism radar tends to beep very loudly. It may well in fact be true that the current suite of mod tools makes beehaw's managers powerless against an overwhelming tide of new traffic, but that wouldn't automatically rule out competitive motives.
Federated or not, Lemmy represents an opportunity for wealth for whoever is best positioned if it ends up being a successor to Reddit, and what we're going to see is a round of jockeying and vying for position in the coming (ongoing) chaos. I'll admit that like many of us I'm very new to this platform, but the fact that defederation is possible at all leads me to believe that less scrupulous individuals in positions of ownership could with only small effort leverage it to enlarge their influence at the expense of competing servers.
Maybe I'm dead wrong on a technical level; maybe I'm full of shit--I'll admit I basically don't know what I'm talking about except in the broadest possible terms, so somebody please correct me if I'm wrong--but I wonder if this isn't so much about creating an echo chamber as incentivizing people who identify with beehaw's stated ideology to come under its umbrella (with supposed protections for hate speech), and defederation is just a way to force people to make the same kind of unhappy, unnecessary choices many of us just made with Reddit.
EDIT: I really can't thank y'all enough for this. It feels like I'm right back on Reddit. From the accusations that I must be a secret conservative because I dared to question motives to the folks unable to actually engage in discourse without manufactured disdain, it's like nothing has changed at all.
Maybe beehaw doesn't have an axe to grind, but somebody sure does.