For what it is worth, I have used Atlassian’s Confluence product. The developers/webmasters I have talked to like it more than SharePoint, but the point is that Confluence is a direct competitor to Microsoft SharePoint. I don’t have the source in front of me but I have heard a lot (50%+) of Microsoft’s profits come from SharePoint (recurring revenue and it has a significant moat) so if you think MS will play nicely with Atlassian I would think again, that is a high risk to me. But who knows, maybe Microsoft will buy them.
On other products, like HipChat, I think that is a very competitive field from the likes of Slack, FB Messenger, Discord, GroupMe, etc (all of which I have heard of and used, but I haven’t heard of or used HipChat).
But I like the TEAM ticker name 
Rob