Yes – AcuCOBOL had a COBOL development system which was byte-coded like Java (the technical founder had actually overlapped with Gosling in undergrad, I believe) so we already had the capability to copy the compiled program onto most platforms (Most Unix variants, VMS, Win16 and Win32, OS/2, DOS, OS/400, etc.) and launch it with the native runtime. There was also some ability to transparently redirect I/O — you could have any CALL which didn't wasn't in the local compiled code do an RPC call to a remote server, and redirect some or all ISAM operations to either a remote server or (with another license) a SQL database.

Once they had that infrastructure, it wasn't a huge amount of work to package the runtime as a plugin which was configured to enable the remote call & I/O options by default. Which is exactly restating your last point: having already done the hard 95% of the work, this part was straightforward.