Maint. req. light/timing belt

I have a 2000 Accord.   When I start the car the Maint. Required light 
flashes for a while.  I think I recall that means routine maintenance. 
The car has 51,000 miles.  One of the service techs at Honda told me 
once that timing chains should automatically be changed at 50,000 before 
they go.   Is this hype, or should I do that.  Is this connected with 
the light?   It's abouit a $1000 job, so I don't want to do it if it's 
not highly recommended.   thanks,
mm