I don’t think it needs to be integrated into core as such. Gutenberg in WP arguably should have been kept up a plugin - so I’m sure with ClassicPress a better practice would be preferred. However I think there is merit in bundling this plugin with core package download (eg. as Hello Dolly/Akismet were.) Is there a list of plugins under consideration for this?
Obviously with most plugin (feature) areas there are many good existing plugin options and showing this kind of preference would not be desirable (cough GB again.) However, something like this that is well tested, maintained and highly inline with the intention for CP could be. I’m not sure I can think of any other plugins right now that would be suitable in this way. The criteria for inclusion would have to be very strict to avoid any kind of bloat, but it maybe worth coming up with that in case other suitable candidates for this come up in the future.