The textfugu topic on はず does a thorough job of using “expected” and “supposed” interchangeably, which has left me a little confused on the exact meaning of はず. In English “supposed” has the extra meaning/connotation of

be required to do something because of the position one is in or an agreement one has made.

The jisho.org definition

expectation that something took place, will take place or was in some state; it should be so; bound to be; expected to be; must be

indicates to me that はず can be used with both meanings however the textfugu pages were not clear on if there is different syntax needed. For instance it says:

noun + だった + はずです (supposed to have been something)

followed by

noun + の + はずだった, which means “was expected to be something.”

but never goes into any more detail.

Can anyone offer calcification or more resources on this?

Thanks,
red