They won’t know the actual nominees until after the conventions, so they can’t print until after early Aug 2016. Right?
The deadline for getting your name on the ballot for the PRIMARIES has already passed in most states. The ballots have to be printed in time for military and other absentee ballots to be mailed. The deadline to request an absentee ballot in most states is some date specific in February, March and April. So if someone wishes to challenge Cruze’s eligibility to be on the ballot it will have to he done very soon.
Filing suit after Cruze is nominated would be a lot more complicated. Just getting a court to agree you have standing could take years.