I'm not entirely sure (can't quickly find the May report right at the moment), but my point was that China started publishing this monthly report in May, prior to the EOS Mainnet launch. Since that launch (at the beginning of June), EOS has been at the top of all reports released. Hence my statement [emphasis added]:

That makes EOS #1 on this list every month since June

Here is a somewhat more informative breakdown of the top two platforms, and a source that claims EOS was left off the May report altogether [again, emphasis added]:

In the overall category, EOS tops the list, followed by Ethereum. The two projects have been in the same spots since the center’s June update. The CCID noted that when the index was launched in May, the EOS main network was not online yet so the project was excluded from the ranking. Since then, “EOS and Ethereum have firmly occupied the top two [positions] on the list,” the center wrote, asserting:

"At present, EOS and Ethereum are undoubtedly the preferred platforms for Dapp development worldwide, and EOS is showing a stronger momentum. The data shows that EOS Dapp is highly active and user increments are large."

So, yes, I do believe EOS was either absent from the first report (in May), or at least was not in the top spot. However, since June, the platform has held strong in the top position.