The current monarchy format seems like it was necessary at the time of the transition away from pure monarchy in order to prevent too much opposition to the transition from blocking the transition. Like a compatibility layer with a legacy system.
Now the population that would have opposed the transition is long dead, so it seems reasonable to remove the compatibility layer.
Though, a more cynical take might be-- what if there is still latent support for reverting to a true classical monarchy, and keeping a monarchy in place dampens support. I.e. going from "no monarchy" back to "monarchy" might get some people excited, whereas going from "monarchy A" to "monarchy B" is less likely to stir up excitement.
Now the population that would have opposed the transition is long dead, so it seems reasonable to remove the compatibility layer.
Though, a more cynical take might be-- what if there is still latent support for reverting to a true classical monarchy, and keeping a monarchy in place dampens support. I.e. going from "no monarchy" back to "monarchy" might get some people excited, whereas going from "monarchy A" to "monarchy B" is less likely to stir up excitement.