I think it is fundamentally wrong because the whole things assumes that as other "geek culture" things grow, so also should tabletop RPGs grow.
It doesn't work that way.
The portion of the population who will sit around a table and pretend to be an elf isn't really changing. The fact that playing dress-up at social events and pretending to be an elf behind the anonymity of a computer are growing in popularity doesn't not contradict that, nor does it demand any correlation.
Obviously WotC is kicking butt at selling 5E *to the real, existing market base*.
Being a DM has always had its challenges. But the challenge of getting good at it has never been the rate limiting step. The DESIRE to do so is what dominates the math.
I'm sure you could get a non-zero change by making it easier to get started DMing. But if you are looking at the entire population as your reference, the change will be insignificant.
If you are selling bicycles to animals, it might not hurt to increase the ease of learning so that 80% of the monkeys can learn rather than 60%. But if the animals are 95% jellyfish and 5% monkeys then you only gain 1%. And it may turn out that 35% of your monkeys don't care how easy it ease, they just don't want to bother.