The most obvious thing is getting more dakka out of a Wraithknight, but it doesn't take an Autarch to figure that one out.
RAW-wise, Strength from Death is an army-wide special rule. Although vehicles cannot gain a Soulburst action from a nearby enemy unit being destroyed, nothing explicitly states that vehicles cannot perform Soulbursts under any circumstances or that they do not have Strength from Death.
Notable alternate ways to trigger Soulburst include:
-The Reborn Warhost lets "an additional unit" Soulburst when a unit is destroyed. Note this does not state that the Soulbursting unit has to be near the destroyed unit. You "could" argue that "an additional" doesn't necessarily mean that you had to have another unit Soulburst in the first place if you really want to rule-lawyer this.
-Dedicated Transports get the same rules as their formation unless stated otherwise (see: Wave Serpents in an Aspect Host as precedent). Nothing states that an Aeldari Bladehost cannot take transports, and their United in Death rule affects the entire formation. Let that sink in.
-Word of the Phoenix does not include a clause excluding vehicles, and neither does the Soulreap part of Unbind Souls.
You should mercilessly exploit these ambiguous rules until GW releases a FAQ. Notable exploits include:
-The Hemlock can take the Revenant discipline now. As a flyer, it has unparalleled ability to position itself for the Unbind Souls power, punk a largish unit (say, a Conscript Blob or Kroot Bubblewrap), get a free round of shooting with its D weapons, and then either Flat Out (if it didn't Vector Dance) or fire the D again.
-Remember the Night Spinner? You can have it provide close support, either through Ynnari Warhost or Word of the Phoenix. Have it move towards a transport or so. Pop that transport, then have the Nightspinner torrent the passengers. For added fun, take a Crystal Targeting Matrix so you can then Flat-out to torrent a second transport's contents.
-Eldar become the best Tank Shock army in the game due to their ability to move vehicles an additional time. Disregard your foe as you simply shove him off objectives, or play bumper cars. Wave Serpents are hilarious as ever for this due to their Serpent Shield.
Other dirty tricks:
Swooping Hawks go from a cute annoyance to a hilarious anti-aircraft option, provided you can trigger a destroyed unit in their Movement Phase. The Skyburst launcher is cute but doesn't guarantee a kill. Other allies might offer options for "kill in the move phase" (Interceptor maybe?) but the options currently escape me.
-Soulburst lets you blunt the worst effects of Tau. You lose a unit to Interceptor, you get 1-2 units able to pull freebie attacks.
-Dragons are not a suicide unit. You can Deep Strike them in with a Venom and disembark them, slag a target, and use the soulburst action to re-embark, before the Venom flat-outs to a better position.
-Why not consider bringing reinforcements of some sort to gunk up your opponent's plans and give you cheaper chaff to trigger Soulburst? Remember that you're allies of Convenience with Tau, and that Tau have one of the most annoying unit-making gimmicks via the Piranha Firestream Wing.