I need to have the meeting location be configurable based on the meeting type, not based on the employee. 

In other words, our employees can book a phone call, an in-office appointment or at some 3rd party location. 

How can I do this?  

The problem is that, as far as I can tell, I had to choose a location when I created the employee.  And if I can't set a different location for each of the 3 services you suggested (phone call, 3rd party location, my office), then each customer who signs up for each of the 3 services will actually be assigned the one location assigned to the single employee (which was assigned when that employees account was created).  

Am I missing something?

Yes, that helps.  Thanks.  I didn't notice that feature before.

I have made one other "hack" that helps me for not, but isn't ideal.  It might be worth noting for your ability to help others with my situation.

Since each employee must be assigned to a single location at any given moment, there is no flexibility to account for "phone call", "office 1" and "office 2" to be flexibly used without a set schedule.  So my workaround is to

1) make 3 different employee accounts for each employee, one for each meeting location type (phone, office 1, office 2). 

2) link all 3 to the same employees Gmail calendar account.  

3) As you suggested, I then created each service with a reference to that "Meet at Office 1", "Phone call".  etc.

4) Create a "category" that links together all of these 3 employee accounts.  

5) Then embed the catalog-shortcode into the website page for that employee using the "category" from #4 above

These steps present what appears to be one employee to the customer, but it allows that customer the flexibility to choose which location (based on the service) they need to meet at.   

For gig-economy professionals on the move, this location flexibility is a standard use case.  You'll see similar features in Doodle Meet Me and Calendly.  So I submit that you might consider adding location flexibility directly to the service.  And even consider allowing me to control if I am willing to let the customer suggest the location (ie, service=lunch meeting and the customer suggests the location).