I concur.
The original email that was cloned had a CTA button. We deleted that button and replaced it with a new CTA button. However, HubSpot didn’t update the text version of the email. It remained the same as the original email that we cloned. This is ridiculous.
There definitely needs to be a warning message. I can envision a few warning messages. One might pop-up when you first clone an email. Another would pop-up during the review process.