To reflect on the points made in the initial post a bit, the silliness and displeasurable appearance aren't going down well even in the games studio I work at. We're far less able to be expressive in our messages with these, they don't confer the emotions intended nearly as well as the old ones did (Not that they were by any means perfect either!) and they're generally quite a lot harder to read, in part due to the excessive animation at a small scale and due to the fact that often when they finish animating they blink in and out of existence before settling in their unanimated state.
They're not fit for purpose for communication, emotional display or tonality in a workplace, even one as casual as ours where we value the fun and playfulness that the older emotes were providing. I'm not sure they'd be good for these outside of the workplace, either.
The clean icon-like nature of the older emoticons were perfect for their namesake by comparison, 'emote - icons'. These are simply harder to use while also managing to be uncomfortable for many. An option for the old emotes would definitely be preferable.
I'm turning on reduced animations to see if that assists with the more general disruption that blinking emotes brings, but a way of deactivating automatic emote conversion on both the sender end and the receiver end would be beneficial overall, imo.