2.5 yr boy says 7 words. Has said 100.Rec. Lang. Is fine. History fam speech delay. Had glue ear. Autism r/o. Genetic test fine. Therapy didn't help. Worry?

Hearing? Glue ear is generally diagnosed at surgery for tubes. Did he have tubes placed? Has he had a hearing test? I would ensure hearing is normal before focusing on the speech delay. If that is okay i would be sure to get another opinion of a pediatric speech therapist and potentially a pediatric ENT doctor. Also make sure his siblings aren't "talking for him".
If you are in the US. Enroll your son in early intervention services for an assessment of overall developmental ; therapy ; transition to early childhood special education at 3. Learning to communicate by sign language or an ipad picture exchange system while continuing behaviorally-based intensive speech/language therapy is vital. See a developmental/ behavioral pediatrician for evaluation for possible causes.
Try speech therapy. This c hild needs the opportunity to socialize. Ask other children over to your home for a short visit or a trip to the park. Maybe he would like to learn to swim or to splach in the pool. Give him a little time and lots of opportunities to be with others.