No, it won't prune. As i understand it, the patch will make your node reject transactions containing ordinals and thereby not allowing these into your mempool.
As long as there are other nodes broadcasting these ordinals transactions, this will not prevent them from being included in the blockchain, but you are just refusing to be a part of it.
Is this intended to free up memory then? Increase the effective size of the mempool by screening out ordinals?
Unfortunately I don't think it will save you disk space. Its more about your node not participating in recognizing and broadcasting ordinals transactions.
You can read more here: https://thebitcoinmanual.com/articles/what-is-ordisrespector/
Nope, you'll have to prune the witness data yourself if you want to clean up space
