Bon apparemment c'est cuit.
J'ai envoyé un mail à Huawei et ils m'ont répondu :
Dear Sir,
Thank you for contacting Huawei Support.
In order to ensure better user experience, we have fully stop the boot loader unlock code service on 25th July’18 and the same date is already mentioned on our Official EMUI website.
We apologies for the inconvenience caused. Please stay tuned on our official pages for latest updates.
Thank you for giving us the opportunity to serve you better. Please help us by taking a few minutes to tell us about the service that you have received so far. We appreciate your feedback and want to make sure we meet your expectations:
Donc en gros les téléphones Huawei sont à éviter si vous voulez un jour pouvoir remplacer la rom d'origine / rooter ou faire péter les bloatwares.....