You'd kind of expect at least some airing of suspicions and discource on social media, at least. Perhaps not to the extent of Kate Middleton's photoshopped family photo, or the more recent suspicions around Joe Biden's Easter Gathering photo, but at least a few posts. TFS makes it seem that until Stephanie Coombes started asking questions this flew completely beneath the public radar during daytime radio in Sydney for several months, so it's not like we're talking a handful of Aussie rednecks working late in the outback and presumably a reasonable cross section of listeners from different demographics who didn't suspect.
Also, what seems to have piqued Coombes' interest wasn't the audio content, but rather the lack of a social media profile or obvious bio for "Thy" raising some rather obvious red flags. If CADA has taken the time to created a plausible background and social media persona for "Thy" that could be interacted with, it's entirely possible she wouldn't have followed up on it and "Thy" would still be broadcasting with no one being any the wiser. Sure, it's daytime music, so quite likely it's just going to be playing in the backgound in the workplace or whatever, and listeners not really paying all that much attention to it that might lead them to pick up on any audio cues it's actually an AI, but that's clearly the whole point of this "experiment", isn't it?
For that usage case the tech is clearly now good good enough for mass market, and even if they have to stick a "This is AI" disclaimer on it, I don't think that's going to worry them, or their background-muzak wanting listeners, too much, and you can bet this costs an awful lot less to kit out and run that a full-fledged radio recording & broadcasting studio. As the tech improves, I think we can absolutely expect to see it being deployed by more stations, and in more interactive shows with people actually calling in (and no doubt hilarity will ensure when some wag calls in and gets another AI talking to the radio station's AI).