I urge you to go thru with the evaluation. Because of the list of tests, I suggest that they already have a focus. You don't want them to label him without the testing. The tests will rule in or out the areas in which he needs or doesn't need assistance. All of those areas are interrelated.
I also notice that several are focused on functioning and processing. This will tell educators how he learns so that they can focus on a more successful way of teaching. It will allow them and you to form an IEP, Individual Education Plan, that will specifically address his needs. Or the tests may indicate that he doesn't need an IEP. You can be reassured that he's maturing into a more regular school routine.
Which would you rather have? An evaluation that will help many of his teachers to help him focus and learn or have all teachers stumble along not knowing how to help him?
You will have certain teachers who see him in a certain light whether or not you have an evaluation on record. That light is more apt to be negative if your son continues to have difficulty and the teacher becomes frustrated because she doesn't know how to reach him.
The earlier you get started the sooner your son will be successful. The evaluation will change over time and with experience and success.