Preschool question - moving autistic toddler from the toddler class to the preschool class. What would you do?

Looking for some advice, opinions, or knowledge from my fellow parents.

My son is in nursery school 3 days a week, 2 hours in the mornings. Right now he is in the toddler class, which is 18 months to 2.5 years. In December, he will be 2.5 years old, and they are asking me if I want to move him up to the preschool class. They are not influencing my decision in any way (which frustrates meeeee, I need advice!) and are allowing me to do whatever I want.

As I said in the title, my son is diagnosed ASD, somewhere between level 1-2. Physically he's fine, communication he's not, he's very behind on the communication front. Not talking yet, minimal sign language. We're in therapies and all that shit so no worries there. I'm also asking his therapists for their opinions on this.

Anyway, back to the main question: should I move him up to the preschool class? On the one hand, I'm worried it will be too advanced for him, and he'll feel left behind or left out. On the other hand, being around kids his own age/older may present good role models for him, and it might help him with his communication skills to be around more advanced talkers. I'm also a little worried about changing his routine halfway through the year, but it's not a big deal, he will be at the same school just different days and the kids are all from last year's class that he was a part of, so he might remember them. What would you do or recommend? I'm also welcoming any talking points you may think of. Just anything to help us make a decision. I'm not sure what to do.