and indeed, in their privacy policy proper, under section 1:We clarified that we may collect, monitor and record audio and video of your chat sessions with other users to provide a safe and secure environment for certain of our services;
it does say they "may" do this, but they wouldn't add this specific clause if they didn't plan on, or weren't thinking about, doing this in the future. so i interpret this as them saying they will absolutely do it.With your consent, and to enforce our terms, we may also monitor and record your video and audio interactions with other users. When you use any of our services that include these or other similar capabilities we may collect your content in accordance with our terms of use and this policy.
compare this to Discord's privacy policy where, as of right now, they explicitly "generally" don't record voice calls:
i really don't like discord, so the fact that i trust discord more than i do nintendo with voice call functionality really says a lot -.-We generally do not store the contents of video or voice calls or channels. If we were to change that in the future (for example, to facilitate content moderation), we would disclose that to you in advance. We also don’t store streaming content when you share your screen, but we do retain the thumbnail cover image for the stream for a short period of time.