Projects that were designated as A-grade will be automatically re-added to the observing queue upon commencement of the new observing cycle, and they do not require a new or duplicate proposal to be resubmitted. Incomplete projects designated as B- or C-grade are encouraged to be resubmitted

Proposal teams that submit a new proposal to observe some or all Science Goals (SGs) of a currently active but unfinished project will have the relevant SGs identified as a “resubmission” by ALMA. A SG is deemed a “resubmission” if it constitutes a duplication of an active SG following the rules specified in Appendix A of the Users’ Policies and the PI of the relevant previously submitted project is listed as a PI, co-I or co-PI of the corresponding new proposal or the new PI is listed as an investigator on the previous proposal.
See ALMA Proposer's Guide 

For such resubmissions, the relevant portion of the new proposal will be cancelled if the observations are successfully completed before the new Cycle. Observations started in a previous cycle and accepted as a resubmission in the new Cycle will continue to be observed with the setup of the previous cycle.

A scientific justification must be provided if the proposers request one or more additional epochs of observations in the new cycle even if the previous cycle observations are completed. The APRC will decide if such resubmissions are accepted.

A resubmission is not duplication.