Jack, I've seen you sessions running - but I've also noticed that it takes you up to half-an-hour to drum up a training match when there's 600+ in the Lobby. And that's typical. Last time I dropped in on the EU training session the experienced players outnumbered the trainees. I think it would be easier to go into a beginner match lobby and offer help. You might get rebuffed, but you at least know you're going to the target audience and not waiting on them coming to you.
Beginner matches risk ghettoising low level players that are just shit out of luck - always in a game or not online when a session is advertised- or just don't want to put their hand up and say they need help.
I know CAs and the Muse team can, but how many do just drop into a Beginner Match and just ask how things are going, are they enjoying the game, do they need help? If it was my game, I'd have the marketing and community liaison team doing this daily.