Only a very small percentage of their products are great in term of quality/workmanship. The rest are mediocre. Generally overpriced. So, to answer your question, they're luxury brands in term of pricing, but generally not so in term of quality (with small exceptions).
Well the question should be are they "Luxury brands" or "Relative Luxury brands". If you are comparing gucci, burberry, louis vuiton etc to majority of the brands today then yes i guess they would be considered luxury brands, but if you compare them to brands and even themselves 30 or so years ago in terms of quality/workmanship then probably as the above poster said only in terms of pricing.