No, deleted is deleted. You’re OK provided the file is still in source, because more recent backups will have it, however if the file is gone, and every backup that had it is gone, then you’ve missed last chance to recover it.
If you want backups kept for the long term, you can continue specifying larger and larger times and intervals.
Duplicati is very point-in-time-version oriented, and this shows up in the Restore window. You get THAT view.
Coming from CrashPlan you might be used to a view offering per-file dates, and even an option to show files deleted by then. You can also specify deleted file retention handling specially. Duplicati works differently now. Feature additions can be suggested, but tend to get prioritized behind other more important things going on.
IIRC CrashPlan’s risk is in reconfiguration, but it warns about file/folder removals from all your older versions. Duplicati reconfiguration only affects new backup versions. Old ones just age until (maybe) they get deleted. You have to work some, if for some reason you want to delete something from every version of your backup.