If it goes to court I’m sure discovery will unearth a bunch of emails and slack messages pertaining to this as well as documentation about the make up of their training sets and casting and performance notes for the voice talent. Hopefully they’re under legal hold now.
Several possible reasons.
1. They're not actively malicious and have the emotional capacity to feel embarrassed
2. They know they were talking about her voice and making comparisons and that this is A Bad Look and they've had a terrible week PR-wise already
3. Might be a trademark violation, I'm not sure how that law works (in general let alone voice) but there's a reason why Pear Computer had to change their logo