yes
Siphon Life is not affected by Heal Decay but it does activate it. If you use a green and then Siphon life, both are at full strength. If you reverse the order, the green is diminished.
This is similar to reconstruction and healing flames.
As for the entropic chaos proc, I have no idea, mainly because it's horrible and should never under any circumstances be used unless it's for a set mule. It's such a small heal and the % is not worth it, 10% for around 60 hp is 6 hp on average, use the attack every 5 seconds and you're averaging an extra 1.2 hp/sec, and whether it's affected by heal decay or not, it will definitely trigger it the same as siphon life.
tl;dr Nope, but they trigger it for heals that are.
@Sentry4 @Sentry 4
PvP Redux is discontinued, for obvious reasons. Thanks to everyone who helped and joined.
The procs I am mostly interested in are the heal involved with Siphon Life and the Entropic Chaos proc IO.