Yep, as one who has done thousands of flushes, if the fluid is not that bad, and you are not having problems, a "drain and fill" is all I recommend.Now some newer trans have huge,better filters, and changing it is not always a requirement. As I have said before, "flushes" are a huge money maker for dealers and lube shops, and not needed 95% of the time. It's right there with recommendations to change engine oil at 2.500 or 3,000 miles, a huge waste.
On contractors trucks, it was quite normal to see smoked/burnt fluid in the P/S and brake, so it is good to flush them if noticed. Even if you just siphon some out and add new.
Always check the T case fluid, never know how many times "juan" left it in 4wd, and jumped on the highway.