Governments aren't the only ones overwriting old information with new either. The BBC has developed an annoying habit of completely overwriting old articles about Covid-19 with new, semi-related ones, meaning that the only way to see what they were saying earlier in the pandemic is through sites like the Internet Archive.
There's also at least one outright correction that only seems to exist on the Internet Archive now: https://web.archive.org/web/20200428214306/https://www.bbc.c... "Correction 25 April 2020: An earlier version of this article incorrectly said that France had conducted just under 140,000 tests a day by 21 April. The figure of just under 140,000 refers instead to the number of tests it had carried out weekly."
Given that a British "journalist" lost her house to legal fees after libelling someone and refusing to take the tweet down, I think there are reasonable reasons to want to take down libellous, abusive, dangerous, or wrong tweets without having to sue Twitter.
("Journalist" is in quotes because, while that was her job title, she specialized in abuse, libel, smears, and calls to murder, and I'm glad she lost the libel case)
I'm not sure I like this for most users who don't have any kind of following or well developed sense of what is and is not appropriate to post.
I do like this a lot for high profile accounts. It seems fair that if you're verified and have a very large number of followers, you are operating at a privileged level of impact and should lose your right to delete tweets any tweets.
Properly owning up would include keeping the mistake up, so that people reading the apology would actually know what they're owning up to. Without the original Tweet, they might be apologizing for mistyping "2+2=4" as "2+2=5", for all you know.
There's also at least one outright correction that only seems to exist on the Internet Archive now: https://web.archive.org/web/20200428214306/https://www.bbc.c... "Correction 25 April 2020: An earlier version of this article incorrectly said that France had conducted just under 140,000 tests a day by 21 April. The figure of just under 140,000 refers instead to the number of tests it had carried out weekly."