"brand recognition!" The BFG is a brand, homie! Roald Dahl's 4th or 5th most famous book that falls between age ranges and doesn't really have a specific target audience is a brand! They didn't even really push the Spielberg name for that one.
Tarzan is a "brand." Ask a kid who Tarzan is, and he might say "... is that the ape guy?" They literally put out a big budget smash hit Jungle Book movie 2 months ago with Mowgli, who is basically kid Tarzan. That studio had the rights to Tarzan (which has to be public domain at this point, no?) and said "fukk it, let's throw $100+ mil behind i, maybe we'll squeek out a profit!"
"We have a bunch of really excellent tv pilot scripts this year." "Yeah, well we need brand recognition, just make a black tv version of an old John Hughes movie. How could that fail?"