No. A snapshot is a property of a dataset. Each snapshot points to blocks that existed on the live filesystem at the time the snapshot was created. A single block can be referenced by multiple snapshots.
Snapshots never add space. They can hold space that would otherwise free up once the snapshot is deleted.
Here’s an analogy with a truck that has limited space for storing boxes.
You might bump into an issue because of how TrueNAS and zettarepl is designed.
There is no native ZFS feature for snapshot “expirations” and “pruning”.
When you have 2 different replication tasks for the same source and destination datasets, it will either fail or rollback the destination if the destination has newer snapshots than what the running replication task is configured to look for.
It gets more complicated when you want to change the retention on the destination side, but the source has more than one type of automatic schedule. The GUI is not designed for that. The alternative is to configure multiple tasks for the same source/destination, but then you might bump into the issues I explained.
It would be easier to set the retention policy to “Same as source”.