Animation of changing values of map over time using geom_sf and ggplotly does not work

This is a copy of my Question on StackOverflow.

I try to animate changing values on a map over time using ggplot with geom_sf and ggplotly. In the following example the map does not change over time.

library(sf)
library(tidyverse)
library(plotly)
library("rnaturalearth")
library("rnaturalearthdata")

world <- ne_countries(scale = "medium", returnclass = "sf")
world$year <- 2010

world2 <- world
world2$year <- 2011
world2$pop_est <- 1000000

world3 <- bind_rows(world, world2)

# ggplot(data = world) +
#   geom_sf(aes(fill = pop_est))

plt <- ggplot(world3, aes(fill = pop_est, frame = year)) +
  geom_sf() 

ggplotly(plt)

Start with the reproducible R example in the issue and compare how ggplotly handles geom_sf layers with the frame aesthetic. The StackOverflow reproduction is the only referenced investigation; done means the map's changing pop_est values visibly update across the 2010 and 2011 animation frames.