I don't think you can deny them their increments if it was part of the deal for the 5 year pay freeze and 12% pay cut, that they'd get them back this year, they've made a profit for the past 4 (5?) years, so the management don't really have a leg to stand on in denying them the increments.
They are not denying them just delaying them. Pilots need to face the reality they won't get what they want and management are right to push for a better deal and pilots even if they do strike will just have to deal with it and accept lower increments.
In the long term a better deal will be of more benefit to the airline and it's employees.