Yeah the standard "this call may be recorded for quality or training purposes" preamble shouldn't cover for slurping your voiceprint to further the butchering of client service that this call centre is here for.

You would be hard-pressed to find a call center that _doesn't_ start every phone call with a warning that the conversation may be recorded.

Typical call center call is recorded and you are told so by the start of the conversation. I had quite a few of those.