They just released TU3 yesterday that was said to fix some bugs and set the stage for the Lost Archives DLC coming next week. When I check my ACR achievements on my console however, it still has 59/59 achievements and has not added the 10 new ones in yet.
After the update yesterday, is anyone else seeing the new DLC achievements on their console ACR achievement tile?
360 achievements "generally" don't appear until you download the corresponding DLC for which the Title Update was pushed out in the first place. In a small number of cases, some poeple get the achievements beforehand upon downloading the TU though. It is very rare.
Title Updates usually on preceed DLC if there are accompanying fixes for the game. These things cost money to push out on the platforms, so devs and publishers try and bundle patches, fixes and DLC files in a single Title Update.
First Party publishers (like Bungie used to be) utilise a different certification process, and as such, can "hot-fix" things within the platform itself, without the need for subsequent TUs or additional downloads.