Strange.. why don't they use the old route.. very early call, forecasts look good.. winds should be 20-30 mph by lunch.. when people will get there.. even 40-50 on the Gribin isn't an issue.. its a wide ridge.. a lot of guides have a policy of 30mph cut off for crib goch.. which is a much more serious proposition..
If they are that concerned.. delay the start by an hour.. run in better weather..