Timing Belt - Transmission fluid question Honda 98 accord

Hi,
          My car should reach the 100K mark by the end of the year. I
have to replace transmission fluid soon. My question is that is it
worth replacing the transmission fluid or just get it done with when
they replace the Timing Belt? I asked about Radiator Flush/Coolant and
the mechanic told me that is done as a standard procedure when they
replace Timing Belt..so no need to do it now. Does the same hold good
for transmission fluid?

Thanks.