Teacher training is hard. Attempting to schedule even one meeting to kick off the beginning of the season can create a calendar crisis. If your church is like mine, you have some experienced, excellent teachers who really don't need a refresher. They've already used the curriculum.
So why not zero in on the brand new leaders and give them a little personal attention? If your budget allows, take them out to lunch in groups or pairs and walk through the material with them. Give them books in advance so they can look them over and come with questions. Then plan a session together. Actually working together with the material will help them see how the pieces fit together, and it will give you a chance to talk about why they might choose to use one option over another.
In the best-case-scenerio, after you've met together you can pair them with an experienced teacher, or teach the first session with them yourself, so that they can watch and learn before trying it on their own. You probably have leaders that need a season off from teaching--check to see if they'd mind stepping in for just two weeks to mentor the person who is filling their shoes. Chances are they'll be glad to help pass on the baton.
I haven't given up on all-team meetings, but I prefer to plan, pray, tackle decisions, or talk about broader topics like discipline or special events when we're all together, and make the new teacher orientation an on-the-job training experience.