People who are recruiting do so using the methods available to them, ones you mentioned such as macros in trade chat and actively searching on recruitment forums. Guilds that are not doing this are simply not recruiting. So if you’re not interested in joining a guild that recruits the ways you don’t seem to prefer – you likely won’t find any guild at all.
Seems to me you should probably keep more of an open mind when it comes to guild hunting. If you pre-purchase Legion, you’ll receive a 100 boost and can skip the leveling bit you talked about. The thing that will be difficult is finding a guild that needs a resto shaman(though, I am sure they are out there), and you may have to compromise on the level of progression a guild is at. Most guilds farming 13/13 Mythic likely will not need another healer at this juncture in the expansion, as half of their healers are either sitting out or dpsing.
What is your own progression at? If you have no mythic experience, I don’t imagine 13/13 Mythic farm guilds will be willing to take you under their wing and carry you to completion of the hardest content the game currently has to offer. If you *are* 13/13 Mythic, it’s just a matter of locating a guild that is need of resto shaman services. Searching off-server is likely a good bet. Check out the recruitment forums via MMO champion or the official bnet/wow forums, there’s TONS and TONS of guilds looking for PEOPLE in general at this juncture.
Hope you change your mind, because I’m confident there are guilds out there looking for r shams(as they are extremely strong this xpac and look strong in Legion as well).