This would change: nothing.
They'd list their same requirements as they already do on global. How do you think they'd get more people to check the raid on LFG? By spamming global. Same inspection routine would go, and it still takes the time to gather all the players (while making sure raid comp is decent, and that players aren't cheesing GS with off-spec/trash items). So technically it would only create raid browser interface to list raids, and where to apply to raids, this seems nice but it would change nothing.
Having LFG interface would not stop global/trade/city spam.
Having LFG interface would not stop inspections.
Having LFG interface would not stop raids filling slowly.
Having LFG interface would not stop raids being slow.
Having LFG interface would not stop people being removed from raids with inappropriate gear.
Having LFG interface would not stop high GS/achievement requirements.
Having LFG interface would not stop item reservations.
Having LFG interface would not prevent ninjas.
What you're asking is already in the game, but afaik it's not working here: