I'm not sure, their wording around it is a bit convoluted
"... previously unknown zero-day vulnerability in Adobe’s ColdFusion application server. The vulnerabilities have only recently been addressed in Adobe’s APSB13-10 hotfix (CVE-2013-1387 and CVE-2013-1388) which was released less than a week ago."
To me that reads like 'it was a former zero-day exploit", as all exploits are.
Linode brought this issue to Adobe's attention. It's pretty clear that the hack happend 1-2 weeks BEFORE it was announced to the public on Friday. See: http://seclists.org/nmap-dev/2013/q2/3
Not all exploits are zero-day exploits. As I understand it, a zero-day exploit is one that is used in the wild before it is disclosed. Plenty (most) vulnerabilities are only disclosed once a fix has been implemented.
"... previously unknown zero-day vulnerability in Adobe’s ColdFusion application server. The vulnerabilities have only recently been addressed in Adobe’s APSB13-10 hotfix (CVE-2013-1387 and CVE-2013-1388) which was released less than a week ago."
To me that reads like 'it was a former zero-day exploit", as all exploits are.