I'm not saying it can't be accidental (in which case you do what you do when you've accidentally been rude - apologize, correct your mistake and move on), but it is at least careless.
He did interview Danielle a few years back however.(1) So maybe it simply was a careless mistake.
(1) https://www.networkworld.com/article/3130760/elementary-os-0...
It's worth mentioning the twitter handle is still "DanielFore"
As you can see in the linked screenshots. Try to open the old handle and you will find one tweet telling you she's moved to the new one.
Lunduke had this handle on his screen, and either missed it or chose to ignore it on purpose. The former is careless and sloppy, especially if you're trying to do journalism. The latter is very rude, to put it mildly.
I'd argue that by that point you'd be pretty aware.