Worker/message queues or something like Lambda Tasks has been requested a few times, even more than a year back. So Cloudflare already know there’s demand for it, but no dates are promised here. If it arrives it arrives.
Meanwhile, if you need ACID transactions, I’d suggest looking at FaunaDB.
There’s a native driver that will work on Cloudflare Workers as well.
Also checkout Ably, a tutorial can be found here.
Even more here: Realtime support for Workers KV (onChange) - #16 by thomas4