Is this not covered under Arts and Crafts proposal?
Yes. Arts and Crafts explicitly mentions origami in its description, and was created as a way to bridge a number of smaller proposals like these.
This proposal is older than the Arts and Crafts proposal, which explains its existence when there's a broader proposal around.
It's been here 7 months with only 6 questions so I suggest anyone interested in origami follows the Arts and Crafts proposal, adds the Origami questions to it, and/or upvotes any existing origami questions on that proposal.
Arts and Crafts has only been around a month and is already about 40% of the way through definition phase, so it stands a much better chance of getting launched than Origami.