All the CRLs are currently available. If you are still experiencing problems retrieving the CRLs, please verify that your firewall is not preventing outbound requests to crl3.adobe.com or crl2.adobe.com.
The License Server saves a copy of each CRL in the server's temp directory. As long as the contents of this directory aren't deleted when you restart, it should be safe to restart your servers. However, if the cached CRLs are expired, your servers will not be able to serve licenses, regardless of whether you restart or not, until a valid CRL can be downloaded.
I notice that the crls in the tomcat\temp directory typically have months of availability (which is good) until the next update since the last one, and so I am wondering if Adobe's crl servers push out updates more frequently than that so running licensing servers out there don't find themselves having expiring crls when there is an outage of Adobe's crl servers.
Any clarification on this will be much appreciated.
Yes, the CRLs are updated in advance of the next update date. When the Flash Access SDK sees that a CRL is expiring soon (in the next couple weeks), it attempts to download a new version of the CRL. Typically, by that time a new version is available on Adobe's CRL servers, so the license server should not run into a situation where it reaches the next update date, but it has not been able to refresh the CRL.