The market obviously is uncertain on the ban being real or not. There are no confirmations and all media pointedly refer to Caixin as the (only) source.
However one cannot easily dismiss it as a hoax:
* The reporter is not anonymous, stands by the report, and Caixin seems to be a respectable source. Moreover the reporter claims to have seen the document, not just heard about it. And his middle name is not "McGrath"

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* I have not seen anyone question the plausibility of the ban or its details (e.g. the 15-day withdrawal-only period, and the explicit inclusion of the CEOs' personal bank accounts). If it is a hoax, it seems to be carefully crafted to sound very "PBoC-like".
* The PBoC had one full day to issue a denial, but did not, in spite of much asking and media attention. In contrast, when similar rumors circulated on Mar/21, the PBoC denied ir on the same day through its "twitter" (weibo) account.
* When this new report was first published, OKCoin's CEO emphatically dismissed it as a hoax and condemned those who use such methods etc. I have not seen any more statements like that, it seems that the exchange operators are now unsure, too.
* The rumor is repeated on the website of China's main state TV network, and presumably was bradcast by them. It seems strange that they would report a leaked PBoC document without checking and getting an OK from the bank.
On the other hand, the Mar/21 rumors and the Caixin article do seem to refer to the same thing, a "strenghtening of regulations" decided by the PBoC around Mar/18. Perhaps the document shown to Caixin was only a working draft, that in the end was not approved by PBoC. Or perhaps the ban was still under discussion on Mar/21 (hence the denial), but is now approved (hence the lack of denial).
Or perhaps the reporter was duped by a corrupt official. Besides the traders who long for cheap coins, I can imagine a couple other ways in which a large temporary price drop would be extremely profitable to certain people.
On the other hand, if the ban is real, perhaps it was leaked on purpose, to soften the expected reaction from the bitcoin trading community. Namely, if the ban is officially confirmed on Monday, most traders will be already half-resigned to it.