I was alerted to this issue by my podcast host Captivate graciously correcting it when uploading MP3s to them, and it seems to have been an issue since early April 2023.
The duration of an MP3 saved in the metadata seems to be a few seconds shorter than the actual length of the audio file. This can quickly be seen when opening a file in Audition itself, or any other app.
This doesn't cause problems for most apps - they'll simply play back the file anyway - but it confuses podcast hosts and anyone else who might create players based on the metadata. As a result of this, it's causing extra work for these companies.
I'm using Audition 126.96.36.199 on MacOS 12.6.5. I've created MP3s from Audition using both the Match Loudness process and directly saving through the File dialogue and seen the same results - duration metadata seen through "Get Info" on MacOS is consistently inaccurate.