There's a number of challenges to do this well.
@Poker Zombie hit on a couple of them.
First is the video component of the event. If you went with purely overhead, that's relatively doable. The problem with a pure overhead angle for poker is getting wide enough to capture all the action, but still be able to see all the bets, up-cards, etc. Then, of course, you still don't know what folks have in the hole, and poker on TV didn't really explode until the advent of the pocket camera. That means either getting numerous pocket cams on a raised-rail table, using RFID, or just saying screw it...overhead cam only. All of them have some kind of drawback involved.
Then you have an arguably bigger issue to tackle - sound. If you go with a single condenser microphone then you'll get the volume at the table, sure, but it will also do exactly what it's supposed to do, which is pick up the sound from the entire room. There's no way to "mix" that out with a condenser mic. That means going with dynamic microphones, but the problem with those is they, too, will do exactly what they're supposed to do, and isolate the sound that's right in front of them. That then requires numerous microphones with proper position. Going with 2-3 choir-style microphones that hang from the ceiling might be a nice blend of the two, but you're still going to get ambient noise from the rest of the room. Both of the latter two options also require a mixer, and if you're streaming, it needs to have a USB out - and many don't.
And then, of course, there's the upstream bandwidth issue and other possible technical issues to getting it done. Many internet providers don't allow more than 1Mbps upstream which simply won't work. The next common tier is 5Mbps which could be feasible depending on the tool you use to broadcast. For example, I believe Twitch maxes out at 3.5Mbps, so a 5Mbps upstream should suffice provided that nobody else is uploading anything. The problem there is that folks frequently upload pics from their phone to PCF during a meet-up so you'll have upload spikes during the stream that might cut into quality. Ideally you have a 10Mbps pipe or more, but you'll surely pay a little more for that privilege.
In short, live-streaming a specific table at an event *can* be done, but it's going to be both a monetary and time investment for whoever does it.
What might be more interesting - and certainly more feasible - is to use Facebook Live or Periscope to do various live interviews or look-ins, have an on-site "correspondent" take multiple short videos throughout the event and upload/post them, or simply have a Twitch "studio" set up on the side that is indeed live-streaming, but isn't covering a specific table. You could also have Twitch set up to offer a HUD that at least shows things like chip counts/blind levels.
