I don't know, but azo dyes were used in clothing for a while if I
remember correctly so I doubt that these compounds are that high a
risk, also the amounts used in the disks and their volatility etc.
would expose the user to only a few ppm, if that....

I dare say it's been thoroughly tested, I wouldnt' worry, but an
interesting thought.

It's hard to find out exactly what the manufacturer's are using
(proprietary blah blah), but they are called "metal azo" dyes.  They
are probably complex aromatic molecules with side groups containing N=N
bonds, and the whole thing is probably coordinated with a metal ion,
which gives conductivity and the distinct color.  I doubt there's any
health hazard, since they should be present in extremely small
quantity, and it sounds like the carcinogenicity of azides is due to
their biological metabolism to aromatic amines.  There are several
polymeric layers protecting the azo recording dye, and this is a
different situation then when you're using bulk quantities of dye (the
ones used for clothings are much simpler, less stable molecules -
aromaticity imparts stability, but I bet the N=N bond still suffers
badly on any significant exposure to UV).

I noticed another dye used are phthalocyanines...I work with metal
phthalocyanines, and this whole class of molecules (ferrocenes) are
basically nontoxic, although I wouldn't try eating them.  They're the
same basic metal-coordinated heme structure found in chlorophyll and at
the center of hemoglobin.

The azo dyes you refer to have not been used in most
countries for many years.  The majority of dyes used today
are still azo dyes.  The bad ones were a small minority.
Those used today have little toxicity and are not carcinogenic.
As someone else said, there will also be very little in this application.