Adding answer from MSFT Support Team:

Why is there _delta_log being checked when the function used is parquet.
The _delta_log directory is being checked because the system is designed to scan directories and their parent directories to look for a Delta log folder. This is done to ensure that if a user is writing to a Delta table using the wrong format (e.g., using Parquet instead of Delta), the system can identify the mistake and fail the job to prevent data corruption

Why are all parent folders getting _deltalogs call?
The system recursively checks all parent directories for the _delta_log folder to determine if any of the parent directories are Delta tables. This is part of the design to ensure that the correct table format is being used and to avoid potential issues with data integrity.

What are the files _encryption_metadata/manifest.json and _spark_metadata being referenced for given that is not present in the folders.
How to remove this requests?
The _encryption_metadata/manifest.json file is being checked to determine if encryption is enabled on the storage.
The _spark_metadata directory is typically created by streaming jobs to store metadata about the stream. Even though these files may not be present in the folders, the system checks for them as part of its standard operations.

How to remove these requests?
Currently, there is no direct way to remove these requests as they are part of the system's design to ensure data integrity and correct table format usage.