。
We should know the result by Thursday.
Literal
Thursday by-までに-は result [subject-が] become-clear [should-はず] is.
~はずだ is the expectation marker — 'is supposed to / should be the case that.' Distinct from ~べきだ ('ought to morally') and ~でしょう ('probably'); はずだ marks something the speaker has reason to expect based on prior knowledge or arrangements. The 結果が分かる construction uses が because 分かる takes its understood object as its grammatical subject.