Yeah but a lot of it seems to be driven by irrational fear.
There is no logic to Auran deleting 98% of content. That should have been a red flag that would have eliminated most of the hysteria here. If you believed for one second that Auran was going to delete that much content, then you should believe that I'm an ex-Nigerian prince with $50,000,000 in the Bank of Nigeria. All I need is $5,000 from you and the rest is yours. Go ahead any buy Auran...
Now, craziness aside, as I understand it, there is/may be stricter error-checking for uploads. That's a good thing, for all Trainz users, not just 09/10.
As I understand it, you still can upload content with 04/06 version numbers, as long as that content can pass the stricter error-checking, which so much said content from the past could not. Please correct me if I'm wrong, with details of your rejected content.
Unless I am unable to do so, I am interested in backdating my creations for backwards compatibility.