Please explain: "MC015 Security notice: eBay listing removed"

[nolemmings]

I received the above message for each and every one of several dozen hockey cards I bid on from a seller with 32K feedback at 100%. It goes on:

Hello nolemmings (taslegal@hotmail.com),

We're writing to let you know that this listing for an item you won or bid on is no longer available:

320842787711 - 1972 Topps Vic Hadfield New York Rangers #110 PSA 9

We understand this may be disappointing, but occasionally we need to remove listings. In some cases, the item itself is fine, but was listed in a way that didn't follow eBay's guidelines.

It can't be the listings, because they parroted those from last night, where seller offered dozens of cards from the same set with the same, rather minimal and innocuous listing language. In fact, I won 17 of those cards.
I'm reluctant to pay if seller's account was hacked. I'm unhappy about the whole thing anyway, because I was planning on bidding strong on today's auctions so as to knock off a large % of the set (what can I say--I've got a soft spot for '72 Hockey). Now it seems as if 17 is the most I will get, and I wonder if those are even legit.

The auctions were set to expire in just a few hours, so it's not as if Ebay acted quickly. Is this just a failure to pay ebay fees by seller; if so, why doesn't his account show as NARU? (Seller is psa-set-guy, member since 1998)