You didn't specify which airports you were talking about. If you are using default airports, then yes, you need to have GSX Level 2 in order to have SODE jetways for those airports, but you already need to have GSX Level 2 anyway in order to see animated passengers. If you are using third-party airports, you would have to check with the developer. There are a lot of third-party airports that already have SODE jetways, so you don't need to do anything more with those.