I don't think I've ever referenced a real brand name in something I've gotten published, the issue just never came up. So I can't speak from experience with a publisher there. But I've read plenty of book and articles that reference real brand names. It's fairly common for a book to say, "Bob drank a Coke" or "Sally drove up in a new Rolls Royce".
I am not a lawyer, but my understanding is that the two big issues are:
(a) You cannot use a brand name in a way that waters down its meaning. Mostly this means, you can't use it in a way that suggests that it's a generic term for a type of product rather than a specific brand. Coca Cola used to make a regular practice of having their lawyers contact anyone who printed "coke" with a small "c". Owners of trademarks live in constant fear that they will lose their exclusive rights to a trademark. "Escalator" and "Aspirin" used to be trademarks, but the companies lost their rights to them because they allowed them to be used generically.
(b) If you say something nasty about the trademark owner, you risk a libel suit. This isn't really anything to do with trademarks per se, but with the fact that you're saying nasty things about an identifiable person or organization. If you say, "Foobar Company is dumping toxic wastes into the water supply", you risk the same sort of lawsuit as if you said "My neighbor Fred Jones is a child molester".
Of course one publisher might be braver or more skittish than another.
It sounds like you're saying that you want to use a real brand name just because the name evokes luxury products, like, "Fred had made it big. So big that he now wore Armani suits and a Rolex watch." I'd think that would be no problem. These companies don't object to being associated with luxury and style.
If you said, "He wore an armani-type of suit", that might get you in trouble. I'd avoid it.
And of course if you said that some company is run by a bunch of criminals, you'd better be ready for a lawsuit.
If your story just has a handful of references to "Bob wore Foobar suits", then if the publisher comes back and objects, I'd think the problem is easy to fix. Assuming you have the text of the book on a word processing file, you find the first reference, make up a fake company name, and add a few words to identify the significance of the brand. Like, "Bob could now afford to wear Foobar suits, a well-known, expensive and high-quality brand ..." Or, "Bob always envied Fred for his expensive and high-quality Foobar suits, but now he was able to afford them himself." Or some such. Then do a search and replace all other references to the real brand with the fake brand. Of course I haven't read your story, but I wouldn't think a change like that would take more than, what, half an hour?
BTW be careful with mass search and replaces. I've reminded of when a certain popular web site decided that they would not allow user names to include the word "Allah" because of complaints by Muslims about disparaging user names. And so a woman trying to register as "jcallahan", "Callahan" being her actual last name, was told that was not an acceptable user name.
If details about the company are woven into the story, of course it gets harder. Like if there's a point where the fact that the name rhymes with some other word is brought up, you can't just change the name. Or if you mention enough facts about the company that it would be identifiable, like you say that the company is based in Florence, Italy and the founder was a former race car driver and that they sponsor a jazz festival every year -- things I just made up, by the way, I have no idea if that describes any real company, but if it did -- then if you can't use the name you probably can't give such details.