Here's the why not: DO has no access to your droplet. And even if they did, can you imagine them having to figure out how each one of their customer has configured WordPress, under which directory, using which web server, on and on.
However, I think this should be implemented outside the droplet. Perhaps at the LB level where SSL termination should be done and all you have to do is run a "One-Click Install LB WordPress SSL." This is straight forward to implement IMHO. The only downside is that the communication between the LB and the droplet would be in the clear. So this carries the assumption that DO's internal network cannot be man-in-the-middle'd