And I wouldn't term them euphemisms -- well, at least, not those done well. But some have truly "passed on."
Arial is not a revival of Helvetica.
According to Mark Simonson Arial seems to be an adaptation of Monotype's grotesque series made by Birmy to match Helvetica's spacing so it could be substituted without disrupting a document's text flow.
Microsoft adopted Arial instead of Helvetica because of licensing and price issues but Microsoft didn't create Arial.
All this I learned at Mark Simonson's "The scourge of Arial".
Héctor, would you please list a print source for that? I have seen the Arial/Monotype Grot connection mentioned many times but never seen anything substantial written on the subject. I find it a curious claim, as Arial really resembles Helvetica whereas MT Grot looks, at least to me, to have grown out of late 19th century light grotesk designs.
Edit: Nevermind, I just found the article.