From my understanding you can play offline (Without the internet) but most events are saved. So if you blew up a space station offline then went online. It would tell the server you blew it up and it's gone(Not 100% sure on this part). Thus screwing everyone else over. So even if anything could be made for the offline part. It should be something that won't damage things if they did go online. Like No damage for players on planets. Since if ships had speed boost from the trainer, people could get to the center of the galaxy and name things (Planets, creatures etc) just by using a trainer. So I guess we'll have to see when it comes out in 3 months if we get a trainer or not.
As Welce said, it is possible to play this offline without internet(if the developers spoke the truth) at any rate as he said, if you do something offline and go online it tells the servers what happened and syncs it to players Like ED it uses a galaxy simulation it also does you can leave messages for other players on planets but you aren't connected to the servers in the sense of Division for example, you play on your own computer and also if you do something on a planet it's saved and with a seed data file the game can create and recreate planets you have visited and the idea as I can understand is that this file is however also sync'd to the servers if you go online. But everything is handled client side and you tell the servers some things to make it a sort of evolving galaxy.