The problem of people with disabilities feeling that the law permitting later abortion for them (us) leads to disablism needs to be tackled from the other end, IMO.
Prove that disabled people are valued by voting for suitable education, support and respite for families, support not discrimination for disabled people trying to work, a benefits system that supports those who can't/need it, that hasn't been deemed inhumane by the UN.
Make a world worth bringing disabled people into, and abortion of viable fetuses will cease being an issue.
In the meantime, I had my 20-week scan at 23.6 weeks, no chance for anomaly tests, and decided not to with my second pregnancy either. But since then I've seen friends struggle for over a decade looking after their kid with severe learning disabilities and other medical needs, and it's broken them. Twelve years of baby-like lack of sleep, violent frustrated kid bigger than his mum, and may well have to go into care soon as an hour or two a month of respite isn't near enough.
I'm on my third tribunal to get my kids an education and may have to homeschool. We should be well-off given DP's salary, but instead have used most of our savings. I only get PIP thanks to getting my MP involved.
If I had to decide again, in the current political climate, I think I'd choose differently and want to avoid a known disabled child coming into the world. Horrible to have to say that, but knowing people will suffer is worse.