An interesting video. I hadn’t realised there were different versions of the Meowbit, the description mentions 1.1 and 1.3.
I can see an HC-SR04 in https://www.youtube.com/watch?v=zCbyED554ro . I think that’s being powered from 5V. That means the echo output will be at 5V and the micro:bit isn’t 5V tolerant. Are you reducing the 5V to around 3.3V or the micro:bit’s supply voltage? You can see that being done in my example and on others like https://www.teachwithict.com/hcsr045v.html
New device: Kitronik ARCADE mentions a bluetooth addition for the Meowbit in SD card form.