Do you think in a way Disney is leveling the playing field for those who live locally (who might not start to get in the mind frame to plan a trip to the parks for a specific time frame more than 60 days prior)? Otherwise they could run into backlash from angry locals who could be shut out by infrequent visitors who, accustomed to how the other park rolls, sit up until midnight or 1 am to make ADRs.
Most likely that's a large part of what is going on, but the end result is a poor compromise, that's for sure.
Also, I suspect that Team Disney Anaheim just assumes that the majority of the locals/people who visit DLR more often aren't in a Halloween mindset way in advance, nor are they in a holiday season mindset way in advance. Last year the Disney Parks Blog didn't even officially announce the start date of the holiday season -- which begins in November -- until September!!!!!!!!



In the past they had announced the date earlier than that, so I have no clue what the delay was about -- but waiting that long to announce holiday dates is not very conducive to long distance travelers planning in advance! It's like Disney just assumes that no one really needs the DLR seasonal info ahead of time (like when WDW info is released), so they don't even bother with it.
But, as you said earlier, now -- of all years -- is a time to release dates and details
early, when people who don't live locally will be considering flocking to DLR to experience all of the 60th anniversary fun. For example, if a family that usually travels to WDW for their annual Christmas/Holiday season trip is now contemplating heading west in December for DLR's Diamond Celebration, they may want to also be assured that certain holiday season events/overlays/activities will be going on as well, i.e., Viva Navidad, Jingle Cruise, Olaf's Ice Rink in DTD, Jingle Jangle Jamboree, etc.
It seems like Disney is tiptoeing on the line between treating DLR as a vacation destination and treating it as a locals-based destination, and they haven't found a good happy medium yet (meaning a solution that would please both the infrequent visitors and the locals).
What's sad is that, more than likely, the dates for all of the other really popular Southern California Halloween season events -- Knott's Scary Farm/Halloween Haunt; Queen Mary's Dark Harbor; Universal Studios Hollywood's Halloween Horror Nights; the Los Angeles Haunted Hayride; Six Flags Magic Mountain's Fright Fest, etc. -- will be announced before we ever get the dates for Mickey's Halloween Party. Without going back and looking it up, I
think that the dates for all of those events were released before the MHP dates came out in 2014. I know that I was already amusing myself by reading the colorful, vivid descriptions of the Los Angeles Haunted Hayride's Echoes from the Rift 2014 event before I knew what was happening at
Disneyland.
But, again, the Disney Parks Blog -- for some wacky reason -- thought that people didn't need to know 2014 holiday season dates (and people often treat their holiday trips as a
big deal, as those may be the only trips they take all year) until September, even though the season was starting in November! So, when I take that into consideration I suppose it doesn't seem too shocking that they would wait until June or July to start giving us morsels of Halloween Time/Halloween party info, when the season will begin in September.
The good news is, I don't think that Disney can wait any longer than July to reveal info and put party tickets on sale, so we know that in 3 months we will definitely know something, if not sooner. I could be misremembering this, but to the best of my recollection I don't
think the Halloween party tickets have gone on sale in August since back in the days when the party was still held at DCA and didn't begin until early October. I think that when the party moved to DL in 2010, the tickets went on sale earlier because the party started slightly earlier (late September).