User blog comment:DaNASCAT/Technical Update: January 6, 2016/@comment-1474707-20160110234717/@comment-452-20160115160738

"it's not always possible to time changes in that way."

While I can see that if there was a security issue, it would be pressing to remove the old functionality immediately while a new version is developed - but no such excuse has been presented in this case.

Why was it so urgent that Top had to be immediately removed without a replacement?

""Top" had not been touched in many, many years - it's quite likely any data there may have been misleading."

Every time I've looked at Special:Top/popular (or whatever it was), it has been the same as the top pages list on Special:Search, the popular pages reported by the API, and now, the sorting of the list on Insights. (Incidentally, since the lists on Insights are already sorted by popularity, the creation of Insights\popular should be a 5 minute copy/paste job.)