Although page depth was not really connected with the current trend,  Personally, I think page depth is no longer a reliable metric for comparison, here is why I think so.

Assamese Wikipedia ( 312 articles) : page depth is 339 . 

Sindi ( 355 articles): 381

Compare this with 

Bengali ( 22,062 articles) : 374

Malayalam ( 16,414 articles) : 320

It is self-explanatory...

Technically 1 million edits is a cute milestone ( congrats to ml wiki) to take notice, but we cannot consider it as real metric for comparison among Wikipedias. There are language Wikipedias where Google translation/Machine translations or bot created articles are banned or controlled tightly. There are Wikipedias, where they have a free run. Please note that I am not saying taht they are either good or bad. There are Wikipedias where constant updation of articles happening, due a vibrant Wikicommunity. There are Wikipedians who like to work on the articles offline and then bring it live with a single edit. 

Having said that, it is advisable to do what each community feels best for their language Wikipedia. Of course, it is good to have an healthy competition :)

But everybody, please do continue to report such interesting milestones and statistics. We all love that..