finally

Setting all three to the empty value is nice, as having just some of them set could cause debugging confusion.

except FileNotFoundError as e:
 ...
 model = None
 label_encoder = None
 expected_features = None
except Exception as e:
 print(f"An unexpected error occurred during artifact loading: {e}")
 model = None
 label_encoder = None
 expected_features = None

But DRY suggests that you write it just once:

except FileNotFoundError as e:
 print...
except Exception as e:
 print(f"An unexpected error occurred during artifact loading: {e}")
finally:
 model = None
 label_encoder = None
 expected_features = None

Actually, looking at the slightly long list of filenames that appears in that nice diagnostic message, perhaps we'd like them in a single list that can be used during loading and error reporting.

Looking at the slightly long list of filenames that appears in that nice diagnostic message, perhaps we'd like them in a single list that can be used during loading and error reporting.

f-string calls str()

f-string already calls str()

There's no difference in the behavior of these two lines:

There's no difference in the behavior of these two formatted string expressions: