This depends a lot on the company and the actual business of the work getting done. As you've noted in the comments, "Diversity and Inclusion" initiatives very commonly and often devolve into people who don't know their asses from a hole in the ground white-knighting on behalf of people who really don't need "allies", and/or into bureaucratic nonsense of people who do actually know things but do not have authority suggesting things to people who know nothing but have authority and being shrugged off because the people who have authority think they also have wisdom but don't in fact know anything. Which is all to say, it's very possible, as in many other examples (many of which you've noted in the comments that you've seen in other posts/questions here), that this is all a farce and you're being included as "the token disabled guy" just to waste your time.
Of course, it could also be the case that your company is actually serious, and will seriously consider the suggestions and recommendations of this team and actually make efforts to do what this team suggests. Another pitfall that might happen is, for example, this team talks about some pie-in-the-sky multi-billion-dollar solution to some problem, and when you go to the execs for funding, they're like "oh, here's a tenner, do what you can" (I'm exaggerating, but you get the point). From the perspective of the DEI team, you have to make sure that you're actually being realistic with what you suggest to management, and don't waste your time with fancy pie-in-the-sky ideas that will never get funded. Not that you have control over what the DEI team says or does, but this is something to be aware of, and if it seems like the general vibe of the team is in this direction, you may want to excuse yourself. Conversely, you also want to make sure management is serious; if you propose a reasonable solution with reasonable budget and management declines it out of hand, then you may also take that as an indication that management put this team together as a farce and it's a waste of your time, and you can excuse yourself for that reason as well.
Since you're on this site and active and have a high rep, I'm presuming you're a pretty smart guy. Which means you're going to put forward real, actionable, good solutions for people with your disability. That said, be careful that you don't get shouted down; if your reasonable voice gets shouted down by unreasonable voices (those "white knights" or "pie-in-the-sky ideas" mentioned above), you may also find this effort to be futile and excuse yourself.
The above has mostly focused on the pitfalls of such an endeavour, mostly because that's where the problems lie. Of course, it's entirely possible that your company is the company that actually does these sorts of things the right way and you can actually make a positive impact. I'm not trying to say that DEI teams are bad and you shouldn't do it; what I am saying is to be careful and make sure that your time isn't being wasted on efforts that management really couldn't care less about, and also to make sure that the company's money isn't being wasted on efforts that don't actually matter but make a bunch of white knights "feel good". Basically, you should go in, try it out, see what this team has to say, and if you feel like it's good then go for it, and if you feel like it's a waste of your time then politely decline.