It depends on the quality of the codec used by the VM system. Any compression is likely to destroy the code. VoIP protocols usually send DTMF as specific messages for this reason. However I wouldn't be surprised if it worked.

It would be interesting to see if the DTMF tone could be recorded, or if the voicemail system would capture it first and abort the recording. Maybe it depends on which tone is played?

Investigating the extra A, B, C and D DTMF tones may be of use in this scenario, just in case voicemail systems don't recognise them as commands but 2FA callbacks allow them for confirmation.

People don't tend to read comments - I asked about this same thing below, but, for example, PhoneFactor, uses the #, which is often used to end recording, so, "any key" is dangerous, # is not as much.