So i upgraded today to the nest aware pro because I'm assuming my trial ended. So i upgrade and then all my previous data was all lost. I literally had videos i needed to watch because someone i didn't know came to my house and then everything get erased. Thats the dumbest thing I've ever experienced. Upgrade to a service that gives you 24/7 access and deleted everything i had previously.
If your trial ended, then yes, everything is automatically deleted up until the last 3 hours for the free version. Google is not going to store your past data if you have not chosen to subscribe, just in case you decide to come back later. If you have anything important enough (an event of someone coming to your house), then you need to download that event and keep it. Even with the Nest Aware subscription, these events will eventually be deleted after 60 or 90 days.
Also be very careful when signing up for the subscription. You can easily sign up for two subscriptions by mistake on the same account and they absolutely will not refund duplicate subscriptions, or move them to another account, or merge duplicate homes created due to mesh wifi set ups