I assume, that your conclussion is right. Some cache owner has changed sizes. As written in the FAQ, some things takes several days, and sometimes even weeks, (or months for archived caches) to be detected. Most things that involves editing is a part of what takes a long time.
This is because we can not get updates about this via the API in a good way, so we have to find it out ourselves, and that takes some time. And to make it clear, by ourselves, I still mean that it's automatic.
We are also aware of that Project-GC is a bit behind in processing data this week. We usually keep a delay of up to 36 hours (up to meaning that some data will be correct within hours, and some takes longer time). But this week we have a few percent of the data that is 4-5 days old. This is because of some new issues with the API to Groundspeak, and it is something we are working on as well.