Ask HN: Best internal communications tools/approaches to replace Workplace?

Our SaaS company is about 150 people distributed globally. We use Workplace by Meta for all internal communications. I think it's a criminally underrated product; unfortunately Meta management doesn't agree, as it's being end of lifed in August.

Workplace's killer feature is Groups, which are just like Groups on Facebook if you are old enough to remember those. For example, everyone in the company is in a group called Product Releases, where all notable feature changes (on average 2 per day) are posted. There's also dedicated groups for new products or features that are in development, and then marketing, sales, etc. also have their own groups for announcements. Just like on FB, folks can comment on posts or like them.

This seems much better to me than email (because you can see replies if you want to but you aren't forced into an email chain with every post) or chat (it's much more structured and async-friendly).

Workplace is going away in 6 months. We really don't want to switch to a chat-only product.

So my questions:

- What internal systems have folks seen that worked well?

- What tools and/or workflows should we be considering?

- By any chance has anyone used Workplace and then moved to something else that was as good?

As CTO I am particularly interested in this from the Product/Engineering perspective, but we would be looking for something for the whole company.