answer: I believe you will lose data due to the object storing the data being lost on the process restarting.
From async's queue documentation , a queue is an object that then is pushed onto memory and so if that respective node process is restarted the memory associated with it would be restarted as well.
pm2 reload is essentially a restart, but with gracefulness in keeping at least a process up to prevent zero down time.
From a question on the nuances of pm2 restart vs pm2 reload
SO link,
With reload, pm2 restarts all processes one by one, always keeping at least one process running.
