16 months and nonverbal/spacing out

My son is 16 months old and is non verbal and doesn't comunicate well.
He babbles and laughs but he's been "saying" the same "word" for over 6 months.
Mama
Dada
Baba

But he doesnt connect them with what they are,he just says them.
If he wants something he cries and points and bounces.
And sometimes he just blanks out and stares at something without binking or moving.
He went to a speech therapist 2 months ago and she evaluated him and said he should be improving and wants to see him in june.

His pedi is concerned and thinks he may have a speech delay caused by neurfibromatosis (which I have) so he's going to the neurologist on Thursday.

He's really smart,can follow comands,find certain toys,and knows 3 body parts when I say them.his hearing is fine he just can't talk.

Part of me thinks its totally normal toddler behavior but in the back of my head I think maybe something IS wrong with him.

Has anyone been through this that can give me some advice

My son wasnt really saying much at all at 16 or 18 months. They sent him for evaluation for autism/speech delay etc. They did say he had a speech delay. But now he is 3.5 and talks pretty good. Not perfect sometimes but definately doing sooooooooooo much better.

My son was in speech for a year and still didn't utter a word till he was 3. He was "very delayed" in all the milestones according to the charts. He didn't point and would have meltdowns all the time.

My son didn't start really talking till he was about two. He is the second child and had ear infections a lot. But he could also do what your son is doing by following commands he just wouldn't talk. I started making it to where he had to, if he wanted a drink he needed to say drink and he could have one. Slowly but surely he started talking. Now at 3 he won't stop talking!!! Lol