[quantile12]

No - focus on communication that adds value to your company and your career. Don't get sucked into distractions. Spend your time aligning yourself with projects, ideas, people etc that will boost your career

Is isn't 2018 any more. Don't ramble about off topic casual stuff somewhere where it's all kept on record and easily viewable by your boss (and if your boss isn't invited to the channels, what do you think they'll think when they find out all their employees have lots of 'rambling' channels?). What if HR gets wind of this during the next planned RIF? Your job is to add value to the company

Take your project ideas etc directly to your boss. Don't let other people steal them

Join a non-work Slack group for this kind of socialising