First off, let's make sure everyone's aware that Gary is not out of work. Back in September, he was hired by Charles Schwab as their Senior Director for Visual Communications.
Happy to announce that I have formally joined Charles Schwab as their new Senior Director for Visual Communications. Yay!— Charlos Gary (@charlosgary) September 18, 2014
Though he was understandably excited about the new gig, he that Cafe con Leche was coming to end not much later, if he didn't already know when he took the Schwab job. Note the dates on these two Tweets from him...
Suddenly feeling good about the future.— Charlos Gary (@charlosgary) September 19, 2014
Eu me sinto muito triste hoje porque meus desenhos animados está terminando— Charlos Gary (@charlosgary) October 27, 2014
(That second Tweet translates as "I feel very sad today because my comic is ending" in case you're wondering.)
Gary's next Tweets are some minor clarifications and several "thanks for your support" messages. But the interesting one comes a couple weeks after the last strip was published.
Like I said before, there's a chance that it might come back at some point. Albeit at another syndicate. No hating, just truth— Charlos Gary (@charlosgary) November 20, 2014
That it might come back "albeit at another syndicate" points to the idea that Creators Syndicate is no longer willing to support the strip. It does not seem to be an issue bewteen Universal and Gary himself, as they're continuing to syndicate Gary's other strip, Working It Out. (Although it should be noted that that strip has been in reruns since April 2012.)
So what it sounds like is that newspaper editors are uncomfortable testing the waters very much on the comics page. They'd rather have a more generic comic that they already ran four years earlier than a new one that deals with a nearly unique topic for comic strips. What choice would Creators Syndicate have but to drop the one that (one presumes) is costing them more money than it's earning?
But what does that say about the newspaper industry? By all accounts, newspaper circulation is in something of a death spiral and, rather than try anything new that might change things for good or ill, newspapers would rather go the "safe" route of keeping the status quo, which is all but guaranteed to end in oblivion.
And from a creator's perspective, why would you want to launch a new newspaper strip at this point? It's almost inevitably doomed to fail. At least launching it on the web provides some hope that it might be successful.