If a new contract is worse than an exisiting one the employee must agree to the change. SLS is a variation to the contract, which reduced our pay, so you had to agree to it. The company couldn't force SLS onto us and they can't force a new contract onto us.
They could offer a new contract and reach agreement with the AOA that it be recommended to the membership and voted on, but as we no longer (thank f**k) just rely on a simply majority, a contract which cuts from non-POS18 pilots is unlikely to pass. They would also have to offer a new contract to non-AOA pilots, who could refuse it.
Yes, they can change their policies (housing, education etc) as they see fit.
If the money is running out the COSs are clear. Last on, first off. They will want to avoid this as it costs money (severance pay, transporting aircrew back to home countries etc).
The way out of this is fast and reliable virus testing as part of the check in process and arrival procedure. Immunity certificates may also free up citizens to work and travel more freely. The current bans won't last forever, hopefully there is enough money to carry us through so we can then reap the profits in the new world order.
Don't worry about what you can't change.
If management get creative with the contract at the very least demand something in return (a meaningful profit share scheme like we used to have would be a good place to start).