It's really odd to hear folks arguing against elaborate social media campaigns targeting certain market segments - even niche ones. That's basically the core of the modern advertising industry.
And while the gp might not all engage with complex social media campaigns focused on the original houses (which, I'll note, are THEMSELVES IPs), some will, and its a useful way to create "superfans." Speaking of "superfans," they certainly can't be the events primary focus, but they also shouldn't be taken for granted - that's what WDW has been doing for years, and its a questionable tactic at best.
Legacy bought up the event merchandise that, in many cases, is aimed at the "superfans," the ones who know the lore and follow the announcements, and that merch brings up a key point - if there are enough "superfans" to warrant whole merch lines, there are enough to engage with in the run-up to the event.