The latest version, 38.7.2, is not what is requested through the download link on the PA page for Thunderbird. It is still coded for 38.7.1 and is labeled that way on the page. I was able to get 38.7.2 by copying the link and editing the 38.7.1 to 38.7.2 in it.
All 4 Thunderbird pages are linking to 38.7.2. I just verified. Were you logged in when you checked (it can be cached for 15 minutes)?
Sometimes, the impossible can become possible, if you're awesome!
No, I was not logged in. Thunderbird had been giving me the "Upgrade" message for a day or two. I did not check on the date of the PA posting about the upgrade. It shows correctly now for me, logged in.