In my experience, the only major chains with seemingly “legit” brand-name toiletries are some Regent/FS’s with L’Occitaine, St Regis with Laboratoire Remede (even though that is essentially a home-brand), Park Hyatt/Fairmont with Le Labo, and anyone carrying Aesop. FS Sydney’s Appelles is also quite good.
Personally, my favourite hotel toiletries are definitely those from L’Occitaine and Aesop.
Not sure where WA sources their Tuscan Soul these days, it’s been two years since I’ve last stayed at a WA. But with regards to Salvatore Ferragamo in particular, Tuscan Soul is part of their ‘Parfums’ venture, which essentially is a separate company under the Ferragamo brand.
’Salvatore Ferragamo Parfums’ is usually the name licensed for third party uses — toiletries, amenity kits (Avianca/EVA etc).
Additionally, in my experience, most of Hilton Worldwide’s toiletries are sourced from the hotel toiletries suppliers Sysco.
To be fair, London’s The Dorchester sources their Aromatherapy Associates toiletries from Sysco.