I've also wondered what the purpose is of the date of joining and number of messages being shown (most forums do it), but enough changes for the mo methinks. I'll miss the laughing emoji though. It always made me smile just seeing no matter what the post was about.
We did consider both of these options as well.
Join date is helpful for identifying members, especially those with no avatar (or worse those who continually change); it's also helpful to us when merging older and newer accounts not to have to go 'behind the curtain' to see which was the original
Message count is harder to justify, if I'm honest. One point is that it's useful to know who is a veteran member, not so newbies should quake before their majesty, but so they might have a better idea of whether someone is offering sage advice or not.
At the same time, I don't think it's outrageous to grant a little numerical kudos to those who have contributed the most to the community over the years.
We could, I concede, take a couple more steps towards becoming ethereal creatures of pure disinterested debate who consider only the argument in the present tense, but, as you say, we've just taken more steps than most other forums in that direction.
As ever, changes remain subject to review and revision.