Or is the Navy really worried about Sub-launched SAM's?

The answer to both questions is probably "yes."

Why? So far nobody has fielded a sub-launched SAM system, and given the
difficulties found in the experiments (mast mounted blowpipe, for
example), it's unlikely that anybody is going to try again in the near
future.

There used to be a photo of a purported SUBSAM in the sail of a Kilo.
Other units were rumored to have it. I doubt it would be all that
useful, but I wouldn't want to be two MAD runs into my attack and find
out we were wrong about whether or not the system exists.

The "mine"-type SAM as described by another poster is, in my opinion, a
viable alternative that fits neatly with a suite of other
countermeasures. While the helo is stuck in a dip, their acoustic
signatures are detectible for miles and this could be exploited. I
like the idea of a high-alt drop on an unalerted sub, but I cringe to
think of the IFF issues. A torp can't tell a cowboy from an indian.

v/r
Gordon
VS-31, HS-5, HSL-33, CTG 72.8 (Diego Garcia ASWOC), COMASWWINGPAC plus
a couple other ASW units