You're generally right, but I take issue with the claims: "philosophy does not normally deal in absolutes it is impossible to say the later philosopher is now more correct and worth reading instead of the earlier philosopher" and "Neither answer is factually wrong or right".

I hope you and everyone else realizes that these are philosophical claims, and controversial ones at that!

I would tenatively assert that the majority of philosophers now and in the past have believed the following two things: 1) moral statements like "murder is wrong" are objectively true or false. 2) philosophical statements are also objectively true or false.

(Note that I say "objective", not "factual" as some people would make a distinction between the two, as in the fact-value distinction).

Like any philosophical issue, there is a lot of debate. But when characterizing what philosophers think, how philosophers act, you have to make clear what's your own view, as opposed to settled fact.

That said, I agree with you the central claim that the works of historical philosophers are often of equal or greater insight than contemporary work.