I don’t see how. PIC S3 was about the TNG legends. Legacy is not.It would be a slap in the faces of Seven and the Enterprise-G crew if they have to keep constantly hauling the TNG crew out of mothballs whenever there's a problem.
In Legacy, the TNG crew would be where Scotty was in “Relics”. Still have something to offer, but generally, out of touch with the times. They shouldn’t be used to using holographic controls, or the Ent-G cloaking so freely and frequently. Or really grasp the proto-drive from PRO. Or struggle with new technology such as nanogel, quantum transducers, and polaric warp conduits, which is not new by the time of DIS S3. Or the galaxy more closer to a TOS environment than a TNG environment.
And the crew of Legacy is already distinct out of the gate. Legacy should be nicknamed “The xB Generation” since that’s what it is.