"First, it's disappointing to read such rude negativity against an individual."
Sorry to disappoint you. I don't think I've been too responsible for it, but I am kind of negative on him, so probably still disappointing you. I'm not sure why you're so disappointed by it, and I question whether you would be disappointed by similar levels of negativity directed against someone you don't like.
"Second, it's bizarre that so many people seem so well-acquainted with the insides of Twitter's engineering that they **know** that there's no engineering staff left who could open-source Twitter's "algorithm"."
Did people say that? I didn't. I said that, with the numbers of people fired, it will be harder to quickly do the work. They still have engineers and if this was the highest priority, they would be able to do the difficult parts and get it done. I don't think it will be done, not because they can't, but because it's hard and they're understaffed as it is. When there aren't enough people, a lot of things that can be done aren't done because there's a lot of prioritization. Sometimes a task slips around that if it's fast enough, but this would not be fast.
"Third, it's very strange indeed that the commentaries here are unable to distinguish between 'open sourcing the code that Twitter thinks it uses to implement its algorithm' and 'open-sourcing the algorithm'"
This is related to the facts of life as a developer. The algorithm could, in fact, be represented in many forms, but it's certainly not written in a lot of different forms. There's a chance that it exists in two forms: a specification and code that implements the specification. You could release the specification. I don't think that's what they've got. I'm basing this from years of experience writing code for companies, and you never get a specification. You get general ideas, and you figure out what's wanted. When something needs to be changed, someone makes a summary of the change they want and the code is modified to do it. Unless it's a rigorous standard (this isn't), the specification if there ever was one is not updated. This makes the code the single point of truth on what the algorithm does, and sometimes it becomes complex enough that you may not always know what it is doing at every point.
If I'm correct, they don't have any form of the algorithm other than the code. They could have someone read it and write a spec that should do the same things, but that would take a long time and be likely inaccurate. Also, that's the kind of thing that would be done if someone wanted to fake what the algorithm does because a vague spec can be nondeterministic and more difficult to compare against actual system behavior.