Tank healing is to high

[Shurrikhan]

That's hyperbole and if you don't already know it, you should. Nascent in ShB could easily heal you to full off of Overpower or Mythril Tempest, provided you had at minimum somewhere around 6-10 enemies on you. Bloodwhetting is not really an increase in AoE, and compared to what you could do with Chaotic Cyclone+Nascent in ShB, it's actually weaker in AoE(on paper; in practice it's the same). This also wasn't even new in ShB as WAR was doing the same stuff in SB with IR and Steel Cyclone; and likely before that with Bloodbath.

Nascent was a 50% self-heal. It could full-heal you only if you dealt twice your HP in damage in that GCD. And you certainly didn't do n times as much as your ST damage in AoE, whereas current Bloodletter will simply heal for 400 per target.

Note also that any inherent crit skill will auto-crit its heal, too. Chaotic Cyclone's relative contribution is nearly as strong as before. Against even just 8 mobs, it makes for a 4800-potency heal. The difference is that the base is so much higher and it doesn't actually need damage; you don't have to hit for nearly as much to full-heal yourself, even in a single GCD, now as you did then.

In multi-pack AoE pulls, you effectively self-Bene with each GCD even without banked resources. Old Nascent was strong, but not to that degree.

Where Bloodwhetting has actually increased WAR's self healing is in single target, not AoE. The increase in single target though, is greatly appreciated with the sudden(albeit expected) influx of new and inexperienced healers in dungeons.

This is only true if your ppgcd is under 800 (50% thereof being 400). But, IR Fell Cleaves are already worth a relative almost 950 potency, given its modifiers before accounting for crit chance value wasted. Primal Rush is a relative 1444 potency at a 1.5x Crit modifier.

Given that IR is now on a 1-minute cooldown, and you could certainly have an extra 100 gauge (or 50 + Infuriate, etc.) twice per minute, the new version is a decrease in sustain for single-target.

tl;dr: No. It's the opposite. Bloodwhetting's AoE healing floor increased greatly relative to old Nascent, as you'd not likely have been doing 800 relative potency per GCD per target. Its ST ceiling (and total throughput over time unless you utterly bungle it) decreased, as you easily could exceed 800 relative potency per GCD in ST.