Now that Abundance has been fixed, I've done the event a few times and I was unable to left-click the popup to view the details. The overall progress popup when talking to Chel also behaved the same way. For reference, these popups both direct you to left-click the popup to view the details.
When I disabled the Event Toast feature in Plumber, initially the behavior remained the same. However, upon a UI reload, these popups began working as expected. Turning the Event Toast feature back on right after this causes the popups to fail to respond again.
This isn't really a bug which is why I titled it the way I did. Perhaps, if it's not possible to detect the Abundance-specific popups, an option could be added so that Event Toast only blocks interaction with these popups inside dungeons and raids? I realize the feature is already under the "Instances" category, but it is seemingly not limited there.