What difference does it make being diagnosed or not? If you are on the spectrum you are on it diagnosis or not. At least with a disgnosis your therapist would know better how to help you with sny issues related to it rather than just guessing at what they are dealing with & you can better understand yourself too.
After I left my H one of my T's suggested I might have been dealing with a H who was on the spectrum. I researched it & read books on it & everything described my experiences with him over 33 years of marriage perfectly. I sent him an email describing what my research explained. I saw him again for the first time in 11 years this summer. He said when he first got the information I sent he said.....no way but the longer he thought on it the more he realized it was right. Having had an actual diagnosis could have possibly helped him not mess up his life the way he has.