Are the Prophet's words (peace be upon him) in the hadiths: "The Hour will not be established until the Muslims fight the Jews, and the Muslims will kill them," and "The Hour will not be established until the land of Arabia returns to meadows and rivers," definitive statements, or do they have another purpose or meaning?

All that the Prophet, peace and blessings be upon him, informed about concerning the Hour and other matters is true and a reality without doubt, for it is a revelation from Allah. The hadiths mentioned in the question are authentic and firmly established from the Messenger of Allah, peace and blessings be upon him, and their wording is explicit and does not bear interpretation. These are: "The Hour will not be established until the Muslims fight the Jews and the Muslims kill them," and "The Hour will not be established until the land of Arabia returns to being meadows and rivers."