As GM, you need to know how well the players around the table will handle "meta-knowledge", and this is dependant on the players tendencies, how well they work together, and precisely how actionable the information you gave them is. One shouldn't reveal who is a traitor NPC as the next time they meet them they will inexplicably know to not trust him.
It would be better to use this to confirm what the party has already deduced in character but haven't yet confirmed, such as that the Big Bad is furious at the efforts of the heroes and 'something will be done'.
Another concern is timing, I would recommend not putting this in the middle of a session. Put this at the beginning or the end. So before you have established (or re-established from your previous session) where the party is and what is going on, so if the session begins with the party deep inside a dungeon you might actually open the session with an army of Goblins arriving outside the dungeon and the leader of the goblins ordering them inside.
Or as a session is ending, cut away to the Big Bad reacting to the heroes successes. This works as the mental perspective is expanding out as you leave the heroes or zoom back in on them as a new session begins. As you pan out you can show the impact the heroes are having on this world but once you have focused on them then that is where the focus stays for the entirety of the session. The players around the table keep an eye on what is going on on the table and appreciate it as immediate.
This avoids 'taking the players out of the game' as they are already disengaging from the game. But you are able to reinforce the impact of their decisions.
This is the one place where having notes or a script is ideal. As the PCs are not nearby, they cannot interject to change the course of any conversation. Notes/scripts are important here than ever as you MUST be brief. I won't repeat arguments others have made to keep it short. Time how long it takes to say, you should aim to complete the 'cut-away' within 60-90 seconds. Remember, this is a Tabletop RPG, not Storytime. The only purpose of this little expert is to reinforce their game session.
So don't let it be a pointless aside. Have such 'cutaways' have significant ramifications to their immediate circumstance.
One example of a good cutaway would be to consider if the film Indiana Jones and The Temple Of Doom was a DnD campaign. After the cool minecart chase, if the caves were suddenly flooded with water it may seem totally arbitrary to the players. However, if you had begun the new session with a short cutaway describing Mola Ram ordering his minions to break the walls of a dam then the mines suddenly being destroyed by floodwater has added gravitas. This flooding isn't arbitrary or accidental, this flood is sent by the Big Bad.
This can be helpful metagaming, when the players have the flooding apparent to their characters, it's far less likely they will do something silly like completely fail to appreciate that they are at risk of being killed by torrential flood waters. That this is their cue to escape.
There are many other ways other than cutaways to add further exposition. Dream sequences, using the spell 'mind-link', the spell "Ears of the City" to grant a vision of past occurrences or even a literal Divine Intervention as the avatar of a deity shows the path ahead. But all that is off topic, the question was cut-aways.