Answer old question with additional information and updated statements

Question

I saw an old question by chance [link] which was (in my opinion partially) right at the time, but since then there are more facts. Is it accepted to post 1. more information on the original statement correcting it 2. post updated information which might only apply to newer questions of the same type

As an example in the question I referenced, I feel there is missing a clear indication that the server side does not know where to call home. The cell-phone requests this information (and thus registers with the server on where to send subsequent requests). I'd also like add that nowadays phones like the S5+S6 (to my knowledge) have something like stable internet connection detection (it is freely translated "intelligent network switch"), where they switch between those two networks if required/determined according to outside conditions, for example connection quality etc.

TL;DR

1. Is it accepted to answer old questions if any substantially different information is added.

2. Is it accepted to answer old questions if new information / new tech facts come out.

Sorry if this is a question for meta-meta or something like that. I'm still a bit new, but happy to be here.

Answer 1

You are perfectly free to answer an old question with a new answer. New information and/or clarification is welcome, especially with backup documentation and links for the documentation. The OP is free to change the accepted answer, or may have simply moved on.

Another option is to provide a comment clarifying or adding information to the accepted answer.

The idea behind the SE sites is that they end up being archives for information which may be searched for answers, and, as the real answers change as the technology changes, updated information is useful.

Answer 2

Not only is it acceptable to provide new answers to old questions, Stack Exchange encourages it by providing two separate badges as awards for new answers that receive upvotes.

There are several related questions on Stack Exchange meta or the meta sites from other sites in the network. For example: here, here, or here. I can provide more, but they all come down with the same answer, yes please do edit old answers or add your own.