Yes, that is true but you can recall out and lose nothing.
Zerg spent Larvae and Gas for units he can not use.
So you already did a ton of damage if Zerg actually has Roaches out in time to deal with the first 5 Zealots.
If the Roaches come late you will kill a Queen or two and a few Drones or at least deny mining, you can also choose to focus the third and warp in more Zealots.
The MsC allows you to get out with little to no damage taken in case Zerg made enough units to crush your attack.
If he did not get enough unit you can trade very efficiently since Zealots are really strong vs. Zerg early on.
A Queen based defense is not really an option, Queens are too slow to really use their range by kiting. Zealots are actually pretty good if they outnumber Queens by enough, you can always pull back and wait for another warpin to attack with 9 or 13 Zealots while teching at home. Once Zerg has enough units -> Recall.
tl;dr
If Zerg can defend your attack easily, just recall. Zerg either spent a ton of Larvae or gas and in both cases you already break kind of even.