[MiscIdeaMaker99]

Since when was there ever a plan to disable IPv4 on the Internet? Just because IPv6 is around doesn't mean that IPv4 is going to go away.

[bluGill]

That was always the plan for "the future". That is get everyone to IPv6 and then get rid of IPv4. IPv4's days are numbered - but the number looks really big.

[lxgr]

Why would we keep around a whole separate Internet? Dual stack was always only intended for the transition period.

[g8oz]

It's very hard to get rid of old standards.

"The past is never dead. It's not even past"

[lxgr]

Of course there's an incredibly long tail here, but in the big picture, "nobody except some people maintaining a few legacy systems ever need to learn to work with this protocol anymore" is practically the same thing.