Confused about ADOS and school

My 7 year old son had an ADOS assessment 2 months ago, he scored just on the threshold for a diagnosis. At the CAMHS appointment to go over the results she explained that she expected him to score higher due to her other observations but he seemed to be having a good day. Also some of the criteria were hard to score because of his sensory seeking behaviors didn't allow for a clear score, they may have been higher or lower if the sensory behaviors weren't there. This would have either made him under the threshold or over the threshold. Due to this and the fact that he has been making fantastic progress the past year I was given the option of continuing to look for a diagnosis or leave it for a year or 2 to see how he develops and retest if needed.

He has been getting lots support for 3 years now without a diagnosis and I didn't feel getting a diagnosis was going to make any positive difference so I decided to leave him undiagnosed for now and see how he develops. I have no doubt whatsoever that he has delays and needs extra support, he is about 4 years old in a lot of aspects of his development but he has been making consistent progress in his development for the past year.

His school (mainstream) has been fantastic and have a lot of support in place for him. Last week I was telling the school about the results of the ADOS, the school were shocked and think that I should be pushing for a diagnosis as in their eyes there are convinced he has autism. I explained my reasons and they still seem rather shocked/dissapointed that I'm not pushing.

Now I'm doubting my decision and unsure about what I should do.