MRothI imagine in this case yes, it's because it's a dupe brand. There are some dupe brands which are in the database, and as far as I can recall there's no clear rule against adding dupe brands in the Research guidelines. So it's bit of a grey area. There is a list of brands excluded from Parfumo's database, including Maison Alhambra, but the "why" is not listed.
Sometimes there's a post about a brand with specific reasons or context. From what I've gathered it generally boils down to Parfumo admin having to be proactively cautious regarding possible legal action.
Thanks I see the exclusion list now! I'm sad Maison Alhambra isn't accepted... oh well! I can still talk about them in the forum I guess