It is important to note that there are no “trinity” (tank, heal, DPS) roles tied to professions in Guild Wars 2. Instead, professions can equip certain equipment, traits, and skills to fit these roles in group play. While all professions can typically fulfill a variety of roles, some are better equipped to be a healer or a tank than others.
/r/GuildWars2 is the primary community for Guild Wars 2 on Reddit. Don't play some of these professions, but I'd say that's pretty accurate for open world PvEI didn't do this, but if I were to start over, the only thing I'd really care about would be to have one character with 2 disciplines that can craft complimentary ascended mats. so for example weaponsmith and tailor. or armoursmith and huntsman or something like that. right now I can craft 3 ascended mats on multiple characters, but to get the fourth I always have to relog.
Shaman has pretty clearly been a title rather than a profession. Flame Legion shamans are elementalists (in GW1, they could also be monks). Norn shamans are whatever the animal spirit in question prefers, and the shaman abilities are probably more like masteries that are unavailable to PCs than profession skills.