Q: After a year is over in the subscription in iTunes Match, will the music imported from CDs disappear or stay in iCloud?

No, any songs you’ve upgraded or downloaded again are completely safe. The only thing you lose is the central storage — iCloud will no longer stream or download matched or uploaded songs to your devices.

Thanks for the reply...

Question : will my iTunes library still reflect the track ( but as not downloadable )) (as a missing song) ? Or will it be removed from my library as well ?