No, this has not happened yet: until Jon Ericson, all former Community Managers who are no longer employed at the company ceased to be moderators after leaving.

Here are the CMs, past and present, ordered by period of service. This list does not count members of the support team as part of the group of CMs, although the answer is the same even if you do (at time of writing). (Note: current employees [are not permitted to serve as volunteer moderators while employed](https://meta.stackexchange.com/q/340713/377214), regardless of their job in the company.)

**Robert Cartaino** - no  
Was never a community moderator  
No longer employed by Stack Exchange

**Rebecca Chernoff** (also used name "rchern" while a CM) - no  
Was a community moderator (Web Applications)  
No longer employed by Stack Exchange  
Did not return to community moderator status

**Shog9** - no  
Was never a community moderator  
No longer employed by Stack Exchange

**Dori** - no  
Was a community moderator (Apple)  
No longer employed by Stack Exchange  
Did not return to community moderator status

**HedgeMage** - no  
Was a community moderator (Parenting)  
No longer employed by Stack Exchange  
Did not return to community moderator status

**Grace Note** - no  
Was a community moderator (Gaming)  
No longer a CM, but still employed by Stack Exchange

**Aarthi** - no  
Was never a community moderator  
No longer employed by Stack Exchange

**Adam Lear** - no  
Was a community moderator (Stack Overflow, Software Engineering, Literature)  
No longer a CM, but still employed by Stack Exchange

**Tim Post** - no  
Was a community moderator (Webmasters, Stack Overflow)  
No longer a CM, but still employed by Stack Exchange (although continues to act in a CM-like way as Community Evangelist and previously Director of Community Strategy)

**Jon Ericson** - special case  
Was a community moderator (Biblical Hermeneutics)  
No longer employed by Stack Exchange  
Plans to become a community moderator again, but this hasn't happened yet at time of writing and also the question is really about everyone _except_ him

**Gabe** - no  
Was never a community moderator  
No longer a CM, but still employed by Stack Exchange

**Pops** (used name "Popular Demand" until just after signing on as a CM) - no  
Was never a community moderator  
No longer employed by Stack Exchange

**Ana** - no  
Was never a community moderator  
No longer employed by Stack Exchange

**jmac** - no  
Was a community moderator (Workplace)  
No longer employed by Stack Exchange  
Did not return to community moderator status

**hairboat** (also used name "Abby T. Miller" and "abby hairboat" while a CM) - no  
Was never a community moderator  
No longer a CM, but still employed by Stack Exchange

**Nicolas Chabanovsky** - no  
Was never technically a community moderator, but, as the founder of hashcode.ru (the site that became Stack Overflow in Russian), held a somewhat comparable role there  
Current CM

**Taryn** (used name "bluefeet" while a CM) - no  
Was a community moderator (Stack Overflow)  
No longer a CM, but still employed by Stack Exchange

**Juan M** - no  
Was never a community moderator  
Current CM

**JNat** - no  
Was a community moderator (Anime & Manga)  
Current CM

**Catija** - no  
Was a community moderator (Arts & Crafts, Interpersonal Skills)  
Current CM

**Cesar M** - no  
Was never a community moderator  
Current CM

And finally, an honorable mention:

**animuson** - no  
Was a community moderator (Stack Overflow)  
Was also never a CM, but acts in a CM-like way as a member of the support team