myassisgrass is absolutely right, the management is (necessarily) first responsible to shareholders. If the company is not profitable it will eventually become insolvent. This is of little consequence to the pilots if there is a shortage - they simply walk across the road to a solvent employer needing pilots. Labor employed in a company is a cost. Management tries to minimize all costs. They will pay the minimum required to retain pilots, which is why you see pilot salaries creeping up during shortages, especially if competing companies whipsaw salaries to poach pilots from other operators.
There are still advantages to employers to deal with unions, especially if the same union represents a spectrum of pilots working for the same competing companies - less chance of poaching and whipsawing because salaries are fixed for the term of the contract. Less backroom deals, better morale, etc.
On the downside, the select pilots (the "blessed" ones) can no longer expect that "special" deal not offered to other pilots. The union now becomes obliged by law to represent the pilot's interests. Layoffs and terminations also become more set in stone, with the company responding by setting better standards and evaluation systems to keep the deadwood out.
In a case of dispute between the pilot and the company, the union is legally accountable for the representation of the pilot. Depending on how CHC fragments in the coming years it will become a demanding task for GHPA to argue before whatever board of jurisdiction recognizes them for a remedy. Got a problem? Call your union rep, only they can take a grievance up with management. In the case of a labor dispute not being resolved between CHC and GHPA it then goes to arbitration before a labor board. So if you are a Sri Lanka pilot that got his butt kicked by a Malaysian manager because you were working for one of the CHC "shell" companies, your case will come before the ........Labour Relations Board of British Columbia??? Where is that, some small country in South America?
Interesting concept to have a union organized under the jurisdiction of the country where a company keeps its head office - even though that company has no flight operations in that same country and most employees don't work or are resident of that country. So if the CHC head office really does move to Amsterdam the GHPA will re-register there?