It sounds very rude, there's no other way to read it when someone says "newsflash" or "how stupid do you think they are". No where did the parent imply truckers don't use 21st century technology, they just mentioned another option that hadn't been discussed in the article.
I see this here all the time, someone leaves a very rude comment and then they or someone else argues that it might not have been intended as being rude, but there are certain words and phrases that, any time you use them, you should be aware that they will always be interpreted as a rude remark. "newsflash" is one of them. "How stupid do you think... is" is another. Words have meanings and when you use them you should understand how someone else is going to read those words. That comment was intentionally rude, for absolutely no good reason.
I wouldn't assume it to be a rude comment.