Note to developers: In retail WoW (BfA 8.3) today, I was attempting to run around and buy all the classic patterns from vendors, and found the following issues:
NPC Micha Yance in Hillsbrad Foothills no longer exists, so you can’t buy [Pattern: Icy Cloak] anymore.
NPC Brienna Starglow in Thousand Needles is too busy fighting some Tauren to stop and sell me something, so [Pattern: Azure Silk Cloak] is not available anymore either (from Brienna)
Note: I said “(from Brienna)” because that pattern is supposedly still available from a Horde vendor Jun’ha in Hammerfall in Arathi Highlands
Can I get an NPC named after me now please, like Red Shirt Guy?
You’re a bit late to the party. The Cataclysm caused a whole bunch of random patterns to be lost. (Although both the ones you mentioned are still available from Horde Vendors, so you can probably find them on the AH.)
They have slowly been adding stuff back in, but when they do, they often tie it to current content. (So, you can get the looks of some of the old Weaponsmith stuff from MoP content, some stuff was added in Legion.) In your particular case, a special tailor vendor was added in BfA: