This is probably my only public comment on Cultural Appropriation of DOOM part II, because I have very little time or energy these days and so many things are being said, often by people who I admired or liked, that are sufficiently hurtful that I just am not willing to read further developments. (Here's a roundup from last week, and rydra_wong has the latest failures.)
But I can say this.
*points at subject line* The Earth is tilted. Which means we have seasons. Plural.
Which means that, when anyone proposes that a summer of diversity is a good response to the ongoing discussion about racism in SFF—
I hear, "Here, have this nice bone, now go away."
People who are signing up for this project in good faith might consider this: if you want to do something constructive in response to the ongoing discussions, you don't have to wait.
(For further reading: starkeymonster's delicious bookmarks for clueless white people; also my delicious bookmarks on cultural appropriation.)