After the end is beaten after while it gets boring in minecraft and you end up deleting your world, I think you should be able to go deeper in the end. You should make a whole new end with new blocks, mobs, and everything else. Like an end where it is really dark, scary, and has a bigger and better ender dragon or ender boss.This could be an idea for the future or an idea now, but this is just a suggestion.

There are plans to expand the current End with more features. But not now, 1.6.* versions are the redesign so there will not be any major additions until the redesign is finished.

maybe when hardcore ender expansion reaches 2.0.0

It won't, major version will stay 1.*

There's no point to adding a new end if the current one isn't even finished. The dimension will be expanded after the redesign is done, which will probably take one or two more months.

do you think you will add a new end or just close this issue?

i will assume you may add a new end after the first one is finished

I have plans of progression, it won't be a new End though.