Is codeigniter 3 code standards is out dated??

Without going into to much detail. There is a long... history of why CodeIgniter 3 is a lot like CodeIgniter 2 even thou it's considered "new" (by release date and version number).
The CodeIgniter team understands this and now that CodeIgniter 3 is finally "out the door". They plan to update where it makes sense and which looks like it will be v4.

https://github.com/ProjectOrangeBox / https://github.com/dmyers2004