I'm not sure if this recurred or not. Last night I updated to 201503200020, it had a new changelog that included the OpenSSL fixes. I didn't receive an e-mail first (this was not unexpected, they're sent out at 3 AM and this was well before that), I just used the "check now" button.
This morning there was an update e-mail with the same changelog. I updated to 201503200528. Clearly a different update, spaced several hours apart, but the same changelog. However since these were so close, and since I wouldn't have seen 0020 if I hadn't used the "check now" button I would have missed 0020 entirely. I'm wondering if there was a quick fix to one of the items in the changelog and it was reissued?