Typically voicemail recordings shouldn’t require commercial use licenses unless it is for telemarketing purposes or a service used to generate profits.
if it’s a standard ‘thank you for calling… etc… leave a message etc…’ than commercial use shouldn’t be forcibly required by the seller (in my opinion), nor is it really necessary to legally protect that kind of recording. for my voicemail gig, I have it as an extra, but don’t require people purchase it unless it’s for reasons I stated above.
however for my regular voiceover gig, having commercial use included extra is necessary in my opinion. It ensures I won’t use the recording for my own purposes (example; I voice meditations that I could easily resell), and I bear no legal rights to the profits you are generating when you use my voice to sell something.
but it’s not just to protect yourself from a shady voiceover artist (because obviously I’m not in it to take advantage of people)-- If no licensing is attached to the work, others would be just as free to use it and use it to generate profits you wouldn’t be entitled to.
it depends on the seller, but commercial use is nearly always included in regular voiceover gigs whether included at no extra cost, or for a fee. but yes, voicemails, in my opinion it shouldn’t be necessary unless for the points I initially stated.
but just check with your seller, and see what they say : )