It's obvious that a game, that is lower in quality will also get a smaller player base in the end. You can involve a million of "noobs" into the closed beta and give their opinions on the game the same value as the opinions of experts, and in the end, when the quality of the game rather sucks, you still won't get more players to play the game.. because it is just not that entertaining, balanced, or whatever.
So, by giving those "noobs" the option to directly influence the outcome of the game, you will make the game definitely not better, or possibly even worse. Only by giving those guys, that definitely have insight in the mechanics of the game the possibility to directly influence the game, and only them, you will be able to improve the game. So they don't have to "fight" with noobs about "why are there no two king tigers allowed in one game, it sucks that you cannot replace him if you lose it". And so, they have more time to play the game and give constructive feedback, discuss about it with other players that also know what they are talking about and so on. This will improve the quality of the game by A LOT.
And a better game will get more players.
Once the time is over in which you could really change basic ideas and mechanics of the game, "noobs" are totally welcome, because those new players will then start to grow up a big player base and a big community.
I'm pretty sure tho that Relic will make the right decision about it.
I don't think Relic will be influenced by the ramblings or randomnoob123 compared to the feedback they will receive from known CoH experts. Anyone with a closed beta key can register and express themselves in the official forums anyway so that argument is invalid.
I just feel it's better to share all information in one place. That's all.