Strict/narrow question is: Do required fields change, and if so, how?
Strongly related: Guidance/semantics for field data.
At least one discussion thread: http://common-vulnerabilities-and-exposures-cve-board.1128451.n5.nabble.com/Required-information-for-CVE-entry-submissions-td1046.html#none
From CNA Rules 1.1, Appendix B https://cve.mitre.org/cve/cna/CNA_Rules_v1.1.pdf
[CVEID]:
[PRODUCT]: (includes vendor name)
[VERSION]: (affected, not affected)
[PROBLEMTYPE]: (Sometimes CWE)
[REFERENCES]:
[DESCRIPTION]: (Could include attack type/vectors, impact, components)
[CVEID]:
[PRODUCT]: (includes vendor name)
[VERSION]: (affected, not affected)
[PROBLEMTYPE]: (Sometimes CWE)
[REFERENCES]: (Removed)
[DESCRIPTION]: (Could include attack type/vectors, impact, components) (Removed)
[PUBLICATION DATE]: (Added, date public, or timeline of events related to publication)
[ASSIGNING CNA]: (Added, or chain of assigning CNAs if there is a Sub-CNA under a Root doing the assignment)
[IMPACT]: (Added)