[Chiron1991]

But "outdated code" isn't inherently bad, is it? v1 code is still supported by the stdlib and it still does its job, at least until Go 2.x drops.

[ayuhito]

In fact, v1 code usually uses v2 code under the hood, but with different options to maintain backwards compatibility.

You still get performance improvements even if you don’t switch over to the new import!

[Grokify]

A good example is io/ioutil. It's useful to migrate to eliminate the deprecation messages, but you don't need to do it right away.