In the Next Generation episode Galaxy's Child the visiting Doctor Leah Brahms comments that one of the engine modifications Geordi made was to be introduced in the next class starship.
(gazing at the dilithium cradle)
LEAH: What happened here? Who did this?
LAFORGE: You remember, the crystal's been reoriented to adjust the direction of the lattice structure.
LEAH: It's curious. this modification was due to be introduced.
LAFORGE: In the next class starship.
LEAH: Yes. How did you know?
Is it known what that next class of starship was, that this change was to be introduced on?