I want to replace my condensing unit. The original A coil is 25 years old. Was told I need to replace coil as well because R-22 is not used anymore.

With 25 years on the a-coil, I'd replace it too. Newer freons do not work well in older a-coils, the valves are different and the head pressures are much higher in new units. You could blow out the a-coil.

You was told correct.

Yes, they were correct. You also need to replace the line set, or have it flushed, but flushing is expensive and really messy, so replacing the line set is the best option.