Depends on what you mean by connected?

As mentioned, I assume that all Skymap systems have a feed from the aircraft positioning to the entertainment system. There are two other ways they could work: use a dedicated GPS, or (scodier) have the system programmed with flight number and a route map, and have the pilots occasionally update the ETA. That wouldn't show you where you were in the hold over Berkshire, though.

There are a few other touch points. If the ent system uses satcom, it's reasonable that it might share this with navigation/telemetry functions. It's also possible that the same physical wiring is used for entertainment and other functions.

Really it's just a question of ensuring that the division is maintained. Anything mission critical has to be developed and audited/tested to a high level (it doesn't run on a commercial OS, for instance). I reckon the report (the link is broken so I can't read it) is just flagging that everything needs to be checked and tested.