It is clearly mentioned in the rules that
I think you are not understanding that whatever project you are submitting for hackaTRON can have updates during and after hackathon. In example JustMoney team has submitted a TRON based explorer this season. They can still update the quality of their product with more advanced features.
Nobody is expecting new participants to know what was said and done in previous seasons.
I will say this is not even a typical hackathon is it? Where do we have such big prizes for developers and community?
The purpose of this event is to have as many working projects on TRON/BTTC.