Hmm. I don't really think so actually. Carbine has stated many times that the game will have the base trinity (Tank/Heal/DPS). Adding the fourth synergy as a dedication will not only mess with the trinity in 5-mans (Support Dedication removes from a DPS role as tank/heals are mandatory, slow DPS), and becomes over powered in 20/40 mans (only 1 dps removed out of 25 for full support buffs). It's just not logical to have a "support" buffer style class as we've seen in other MMO's. In reality, every class will have "Utility" style skills that can be replaced on the action bar, so what would really be the point of "support"? That's just another term for "healer" if you ask me (in terms of Wildstar).
The "Rifle Class" is supposed to fill the niche of a "ranged tank" supposedly. Because let's look at it this way. Assume everyone has a DPS role because, well, they do.
Esper - Healer
Spell Slinger - Healer
Warrior - Tank
Stalker - Tank
<REDACTED> - Tank
<REDACTED> - Healer
By these ratios, we have the option of 6 DPS, 3 Heals, 3 Tanks, with no one limited to only one role. To add a "support" style to this not only messes with the trinity, but would also break the ideal ratio for options. If each class is played equally (unrealistic, but work with me), there is a 50% chance that one person will role tanks, and another 50% chance that one will roll heals. This will create a better 5 man group scenario than in WoW (Because let's face it, compare the options for a druid or paladin over a rogue or mage. When you get a mage or rogue, you know they are DPS. Get a druid or paladin, they could be tank/heals/ or DPS).
The support archetype is not going to exist in WS. It is instead integrated into every class as utility skills (and in some cases, maybe path skills as well).