Seems that there was an issue if the first batch of receipts were all of the old format, the guys behind pistats.io is looking into it right now[1]

[1]: https://twitter.com/pistatsio/status/580214043715072001

"@matiassingers thanks for your kind words, we'll look at it right now ;)"

This response, if correctly linked, does not inspire confidence that they care about my privacy concerns.

Edit: Looks like mts was addressing a bug?

Yeah, the now deleted comment said something about a bug with the site.