Food for thought
Worst idea though if he will done it that way, he is a very good businessman, but I doubt that he will go that route to charge every verified Twitter account for $Doge and it's going to be monthly? Twitter has other ways to make money though as far as I know, and it Musk wanted to keep this social media then what he needs to go is to introduce something, improved and your food for thought might not be in the list.
Yes, he could be the biggest holder of Doge and we have seen his pushing it very hard to the extend that we call it manipulation.
But he is a smart man and he doesn't want Twitter to go down, he might have few ideas on his own to make it still on the top of the social media game and then continue his manipulation of Doge to whichever way he can.