I dont think this is true, you just wont recieve the GFN allocated for the first snapshot, you will still recieve correct proportionally through the coming snapshots.
what this means is, there is a different ratio for each snapshot.
as will happen in this 2nd snapshot, participants will get 1.66 GFN / 1PHR.
Graphene Airdrop at a rate of 1.66GFN per 1PHR.
A ratio of 10GFN per 1 PHR will be given to PHR holders for all 6 snapshots.
if you skip 1 or two snapshots, I guess all that remains is calculated for the ratio of each snapshot.