We follow #1 and #2 in our company.
I like #1 because it definitely helps create a more open information environment. It often takes a little while when a new employee starts to train them into this. Quite often they will come in and ask all their questions in DM, I'll always politely push them to ask the questions in the appropiate channel.
I like #2 because it keeps the channels quieter when conversations are had within threads.
Something we've done recently is cut down the number of channels. We essentially just use #general and #random now. We're only a small company (<20 employees) so it facilitates a better information flow if everything is in the one place. One thing we also do, is if a thread contains valuable information we will transcribe this into our documentation system (currently confluence)
I agree with #2 and #3, but I absolutely despise the radical transparency mindset. In my experience, it often leads to people pulling threads off topic and creates an atmosphere where who ever is willing to argue for the longest wins. It often feels like the same problem Stack Overflow has where you go "Bob, how do I do X" and someone who is not Bob will chime in and go "Why are you doing X? You should be doing Y." and you end up spending 10 explaining that you're not an idiot, you know what you're talking about, and you just need an answer to your question.
I think in smaller companies where people can set their egos aside, it's possible to make it work, but once you hit more than a few hundred people you're bound to have a few people who are constantly trying to prove how smart they are and they ruin it.
I've said it before, but I also feels very micromanage-y to me. Like, we're all adults, why don't you trust me to use my best judgement on Slack? No one has issues if I book 1:1 meetings, no one makes rules about who needs to be on email thread, what makes Slack different?
Yeah, that's my point though. Once a company hits a certain size, those people will exist no matter what you do. It's just a personality that a certain percent of people have. If it's just one or two people you can probably correct that but when you have hundreds or thousands of employees, it's unreasonable to think you can get everyone to see the problems they are causing.
The way to avoid letting those people interfere is to let me direct message the people I need to talk to. Why are you taking that away from me?
I mean, you can also just pretend they don't exist. Not going to lie, I've seen that happen in Slack threads when someone random is inserting themselves in an unhelpful way.
I think it's a bit rude to just pretend the person doesn't exist and I feel like it would make the problem even worse. This person who didn't need to be in the conversation is now feeling ignored, so you've now got hurt feelings layered on top of what ever other problem you're trying to solve.
Also, I can't control everyone else in the thread. Even if I ignore the person that doesn't mean other people will. All it takes is one person engaging and it pulls the thread off topic.
It just seems weird to me... I hear people complain so often about how meetings (especially big meetings) are useless because they get off topic and it's super easy for a few loud voices to take over, but then we want radical transparency on Slack.
Also, also, I think it's funny that we're still pushing this idea of radical transparency when it turned out to be a total sham at one of the poster child companies for it ("Away"). It ended up being massively toxic and radical transparency was really just a way for management to ensure they could have an opinion on everything and leadership didn't hold themselves to the same rules. https://www.theverge.com/2019/12/5/20995453/away-luggage-ceo...
I've been pushing my org to open channel discussions using the thread feature and periodically will hear somebody say they found what they needed in an previous discussion. This is the way.
I'd challenge this.
IMHO, Slack is pretty decent if one instills 3 rules in corporate culture.
#1 - No DMs. Talk about all work in an open channel. Radical transparency will also make you a better company.
#2 - Keep replies on the same topic in threads. I.e. don't use it like IRC. Conversely, don't put unrelated replies in a thread.
#3 - Post-back end solutions/resolutions. A thread should NEVER end with "I'll DM you" or "Let's talk about this offline"
If these are followed, at some point you reach critical mass, where "question someone wants to ask you" is discoverable in your history.