Why does this lesson teach deprecated code?

Question

Type and language are both deprecated, as pointed out in the lesson
https://www.sololearn.com/learn/JavaScript/1125/

Answer 1

It can be useful if you ever had to maintain an old site (?)
Or you if you ever wanted to use scripting languages other than JS (VBScript for example, you probably won't but still).
It's good to know some of these old features might come handy in the future, who knows.

Answer 2

https://www.sololearn.com/learn/JavaScript/1125/