Audio embed doesn't render on email notificatinos anymore on Atomic sites

[Robertght]

Quick summary

Using audio embeds/audio block on a new post and publishing it, does not render it in the email notification.

Steps to reproduce

1. Open an AT site
2. Create a new post and insert the audio block
3. Add an audio file and publish
4. Check the email notification

What you expected to happen

To see the embed in the email

What actually happened

It didn't render on AT sites.

Impact

Some (< 50%)

Available workarounds?

No and the platform is unusable

If the above answer is "Yes...", outline the workaround.

No response

Platform (Simple and/or Atomic)

Atomic

Logs or notes

The issue is not present on simple sites.

[Robertght]

cc @Automattic/apex