Will University of the people one day offer sciences (chemistry, biochemistry, astronomy...) as part of the programs?

Most universities offer sciences as part of their programs already.

Universities in USA do their best to make of you a person who will face life with more courage. I mean by this that they give you courses you are not majoring in, and have nothing to do with what the intent of your study is. This way, you will leave the place with much more knowledge than before.

If you increase the courses with astronomy, biochemistery (chemistry, physics, and more, are already "a must" courses), and other scientific studies you don't really need, many more years would be required to earn a degree. And this would certainly not be worth the longer time spent with the increased tuition and fees.