The universe is predetermined even if it cannot be predicted. The universe is organized chaos not random. F f f f f ff ff f f f f f ff f f f f f ff f f f f f f f f ff f f f f f f
Everything that happens, has a cause to happen. This cause occurred at some point in the past so can not be changed. Because the cause can not be changed, the effect can not be changed. This is not only true now but will be for future events.
Example: Right now, your reading my example. This was caused by you reading the words that lead to my example, that was caused by you reading my headline, that was caused by me witting the headline and you reading the initial question and so on. Because of these past events, you reading the example was inevitable and no other outcome was possible. Depending on other events of the past, you will either respond or not. For instance if events of the past caused you to disagree with my argument and caused you to want to reply, then these past causes will result in a reply. The same would be if you don't. If past events gave you cause not to reply, such as never reading the question, then you wont.
If we are to determine the nature of the universe we must look at it on a subatomic level with an entire different set of laws. One of those it the uncertainty principle stating it is impossible to predict the movements of subatomic particles such as an electron. So it the universe is random at its most basic level why would that not be true on the cosmic scale as well.
Nobody knows, but from what we do know very unlikely. What if indeed the universe is predetermined from birth. Without the ability to utilise such knowledge where does it get us, nowhere useful. This is but a distraction from the true nature of the universe. But that my secret, shhhh.
If we say “Everything happens for a reason” that would indicate that God (or some other all-powerful person/force) intends for everything to happen that happens.
Let's say it rains, should I be saying, “I guess God didn’t want me to have a family BBQ today?” Does God have some greater purpose behind the fact that we’re out of bagels, so I had to have cereal for breakfast instead? Why would God intend or want a parent to have to cope with the tragic loss of their child? To teach them a lesson?