Here's the reason: they take their community, however small it is, for granted. If you're playing HUT in August, you're likely one of those (small) amount of people who'll still play last years game through the year, in which case you don't matter from a monetary perspective. Even if you bought packs, why bother giving you relevant free stuff then? Why give you reasons to stay? If you are buying the next game and will spend on some level be it the deluxe editions or $20 in packs or $100 through the year, then they already have your money and will in perpetuity. Why pay your content team to make stuff for people two weeks out? I have a hard time believing there's more than a few hundred people still doing objectives or grinding for free content, a few thousand casual players MAX. Even if there still is some hardcore addicts playing like that, they have you - you no longer matter, you're not someone to appease.
Another answer is this stuff, these events and such are planned out far in advance. That became quite clear at the start of this year when things went wrong or the season just played out. A substantial amount of the content this year just does not make sense if you look at is as a reflection of the NHL season. It makes a lot more sense when you consider they have the data or an idea on the most sought after names, the names that get people to buy packs, covering bases on the most popular teams, and just push out content that will have the greater likelihood of bringing in money.
