Honestly, I don't think Disney needs to invest heavily, as they have ran maybe the most successful marketing strategy of all time by establishing an intense emotional connection between guests and their brand (I'm including myself here, I'm probably one of the worst, lol). That's why we all spend so much (and maybe why we all feel like we lost so much). The fact covid-19 still exists will be their biggest hurdle with what happens at the parks.
One of my friends posted an article about how we don't need all this "stuff" companies tell us we need. I was onboard while reading (yeah I don't need this, this, this, etc) until I got to WDW and was like uh yeah, sorry, I do need that - don't go there. But why? I don't really *need* it obviously. But the thought of missing out on our BBB/CRT/pirates league/dessert party first Poly stay with my 4 (almost 5 year old) daughter and 7 year old son this year is heart wrenching to me; it's because money isn't the biggest loss for me with missing our trip and I'd imagine that's how many disney regulars feel.
A few commercials of kids playing with Mickey and dressed as princesses or dining with friends at epcot and we might still complain but we'll all forgive and go =).
If they have issues when they reopen it's more likely it's connected to guests concerned about their health, kids health, and covid-19 because that's bigger than the Disney connection. Maybe they need doctor minnie and mickey commercials. I think this is going to be a rough year for them but once they weather the storm they'll be fine. I think coming up with new options like housing the NBA and minimizing the outflow of cash as best they can are things they need to do right now as a business.