This is changing tho, with avatars and pronouns and emojis that display skin color. Now a thumbs up in Slack is segregated by color. Why people don't see this as an incredibly bad idea, I don't know.
We've got that happening by gender as well - dancing is a gender independent activity, I don't understand why I need to pick a gender to express when I want to say "I feel like dancing".
It honestly feels extremely regressive.
In all fairness, the good old yellow ones still work fine too. It's not like they were overwritten by the constant burden of choosing a race for your ephemeral internet hand.