That should only happen if lawyers become very niche or if those low end cases are subsidizing trials.
I doubt the former, and the latter means the situation is already bad and mainly just the type of unfairness would change.
The outrage there is bails being set to unaffordable sizes for poor people. OP was picking out the case where bail functioned as intended.
The complaint was purely about rich people avoiding jail prior sentencing due to being able to pay bail. This was called dystopian.
We can't just assume it's going to go the worst way. Neither outcome is particularly more likely, and the human element is by far the most unpredictable.
To wit: I was listening to a report yesterday on NPR about concierge primary care physicians. The MD they were interviewing was declining going that direction because they saw being a doctor as part duty and felt concierge medicine went against that.
What the parent was referring to is the fact that if AI starts to consume the low-end (starting with traffic tickets), actual lawyers for trials will become even more expensive, and thus poorer people will actually fare worse because they will lose their already-limited access to human lawyers. Yes, their case might get handled with less hassle and cheaper, but the quality of the service is not -better-, it's just cheaper/easier.