Sometimes the company records only say "left with another company" or "did not muster with the company" or "absent when muster was called". In Newman's case, it looks like he joined the 21st Miss. "Steven's Rifles" and went to VA.
Check records very closely since J.N. Newman was identified as (John) not Jasper. Typos and transcription errors do occur so I would check the records from the 21st Miss. Company C.
But in no way does his transfer make him any less a member of the "immortal sevnth" Mississippi.
7th Regiment Miss. Inf. Historian
"Lest We Forget-The Immortal Seventh Mississippi