As long as they used Genuine Honda ATF for the fluid change, that's a good start. It's always possible that too much damage has been done for a fluid change to actually remedy an issue, but there are exceptions to that. Changing the fluid, especially if you do it yourself, is relatively cheap and a smart first step (as well as an important regular maintenance item) if the transmission is acting differently.
I believe on the older Sportshift models, that the S light - either S3 or S4 unless I'm misunderstanding your post - will illuminate instead of just D4 or whatever would light up on a traditional Honda automatic(not that they're really all that different). Just a way to let you know something is up, meant as an early warning indicator.