I'm sure a case can be made for TATV
The only real charcters to appear are Riker and Troi
It is set on the holodeck on the 24th Century ship Enterprise
I might bet you that TATV will be on Season 7 as extra just like the Tribble disc on Season 2 of TOS. But that is the only episode I can make a case for.
"Defiant" might be an idea to show what happened to Tom Riker, but I really don't think so, because they had the chance to include as an extra the episode "In a mirror, darkly" after "The Tholian Web" and they didn't so, I don't think they think like this. The only two direct episode links between series were the TOS-DS9 Tribble episodes, and TNG-ENT Pegasus/Riker dilemma episodes. I can't think about a third example ...