We switched from a freemium model to this full trial model a number of months ago; our users wanted to trial the full package on offer and we felt this was the best way of enabling that. Apologies if you didn't see the alert box; in hindsight, we possibly should have emailed our users but I don't like emails from companies clogging up my inbox and I doubt you do.
An issue with providing freemium-model saas is that there tends to be a lot of freeloaders - whilst we realise that some users don't and will never require a feature-rich service, at the same time, we are a business and not a charity. We have spent literally years designing and developing this software and would really like to be able to feed our children in return ;)
There are many simple content management systems out there who still offer perpetually free packages and whilst we would obviously like you to stay with us, we realise you have a choice. We hope you continue to use SimpleCMS and choose to fund its development in the future, which looks to be an exciting one.