The US airlines are constrained by their government aid packages that prohibit furloughs until October. After that though most industry observers are expecting wholesale lay-offs and downgrades. Seniority systems in North America require LIFO and open bidding for every position which of course causes a training cascade. Those obligations are written into contracts that did not anticipate a pandemic so there may be airlines that seek relief in the courts including Chapter 11 bankruptcy.
I wouldn’t be surprised to see our government extend job keeper for the airline and tourism sectors.