They could have had time to film a stinger like that...
It got renewed pretty early.
Here's hoping they weren't too optimistic and give us a full story with beginning middle and end this season.
A full story with an end would be nice, but leave the future open for more adventures. A cliffhanger might be a little too optimistic. A first season that ends on a cliffhanger can often cause some regret if the show gets cancelled. Better to save that kind of thing for a later season, I suppose.
I just feel like while they introduced the magical pen, there isn't really time to use it properly this season, so they should just do something to tease it for season 2 (if it comes to that). I'd rather see the Shining Knight actually used properly since they have spent more time setting him up.