The wage subsidy is to encourage employers to keep people employed but it wont save everyones job. Some businesses maybe not be able to pay 80% of their employees wages for this extended period (no income, cash on hand etc) so they may not apply for the wage subsidy. In that case it's a matter of discussing what measures (if any) can be done to keep your employment eg voluntary annual leave or unpaid leave etc. I think there will be additional assistance packages once the lock down period has subsided.
You can't force anyone to take annual leave without 14 days notice unless its agreed upon with your employer. It's always been like that but some employers are ignorant, or try and sometimes succeed to preying upon employees who don't know their rights.