there are additional technical consequences besides simply being able to see posts (without having to log out or create a seperate account for spying), that the change allows for, like malicious false-reports from someone's main account, and potentially direct quote-tweeting to their followers.

it's also unclear if this change allows the algorithm to endanger people by serving their tweets to the people they've blocked, passively giving abusers opportunities to harass them when they otherwise wouldn't.