French acute accents would have helped in both cases.
I think you’re right to feel aggrieved. Accents (and other diacritical signs) are just as much guides to pronunciation as are letters. All right, they’re not used in English --- but when one’s writing, in English, a foreign word which is spelt with an accent, to omit the accent is to mis-spell the word; one might just as well omit a letter. If I’m reading in English about, say, Ambroise Paré, I’d expect the writer (even if he/she were a journalist) to accentuate the é (the same goes for Esmé Percy --- an English actor, as it happens, whose name is spelt with an é).
Sadé is a word of foreign origin. it’s a contraction of the singer’s name, which (according to Wikipedia) appears to be a Nigerian name (in a language I don’t know), spelt with Latin letters using two accents. The lady’s an English singer, but if she wants her name pronounced Sadé, she should use an accent, even when writing the name in English.
Call me petulant if you like --- but If I were reading a menu offering me coffee frappe, I think I’d feel inclined to order my refreshment elsewhere. Of course, lots of people would think I’m just talking crappe. I’m quite happé with that.