I think it is true because if they get the tech right the market could be saturated and voice actors will be in lower demand.
And the situation is already terrible for these workers. >90% of people buy and consume books via Audible which is owned by Amazon. As I’m sure you can guess there is lots of shady stuff going on. Such as (but not limited to) the “Audiblegate” campaign where workers discovered Amazon was engaging massive systemic wagetheft. As situation which is still ongoing to the best of my knowledge.
Audiblegate - main website for “audiblegate” campaign
#Audiblegate: ALLi Campaign Update — Self-Publishing Advice Center from the Alliance of Independent Authors
The Truth Behind Audible Subscription Earnings (2023) - this page has detailed information including correspondence, spreadsheets etc if anyone really wants to dive in - however it appears to have been republished from another source which I can’t identify