Although I don't agree with all conclusions, I liked to read this post and think some critique is extremely important.
You write: EA’s lack of diversity and parallels to colonialism and institutional racism have meaningful repercussions for EA as a movement. When we can’t engage with people who make these critiques, it damages our reputation and credibility.
I think indeed that with the recent shift from the EA movement towards political influence, optics and finding political alliances are increasingly important. EA ideas can resonate with both conservatives and the left, but I think that the (centre-)left is probably the most natural ally when it comes to tech/AI regulation, larger foreign budgets and improved animal welfare.
From my observations the EA movement is currently doing a mediocre job at aligning with the (centre-)left, mainly due to a lack of diversity in the movement (especially in leadership) and the optics of being a billionaire-backed movement. I saw an outburst of different forms of critique on EA and long termism from the (SJ-)left on Twitter in response to the Time article from some of the usual aspects (Timnit Gebru (multiple tweets an hour), Phil Torres) and some people new to me, e.g. Seth Lazar (although supported by Rob Reich) and many others.
As you mentioned CEA already works on the topic of diversity, although I think there is way more to be done. Some ideas (maybe on some of them work is already done):
Regarding the critique of EA being too much of a billionaire / finance-friendly movement:
Without actually engaging in addressing and researching issues related to global wealth disparity, we cause the impression that we are biased in this discussion in favour of large wealth disparities. We should do more research into this potential cause area and interventions, e.g. fair taxation, the rent-seeking nature of the financial sector and the optimal division of wealth created by the (SV) tech sector. If we conclude that those topics are not important, we should have excellent arguments why we don’t work on it. For now it just feels that these topics are not sufficiently discussed. This makes EA too suspicious to be an ally for the (centre-)left