Just came across this repo: GitHub - Heydon/on-demand-live-region
"A tiny module for making screen readers announce text on demand, without a visual change to the interface. "
Notice it has this feature:
"Say it over and over
Each time you use the say method, the extant live region (if it exists) is destroyed and a new one created. This means you can reliably make the same announcement multiple times. This is not guaranteed in other implementations, where a persistent live region is repopulated."