It's standard within Anaconda. I think the subtext is that if you have the students install Anaconda, they should use Anaconda tools. If you want standard python, then install standard python.
Any cloud computing environment focused on data science or machine learning will have Anaconda installed by default (and for good reason).
The sheer amount of complex dependencies and possible errors between build-time configuration and run-time libraries is vast. Anaconda helps people steer clear of a large amount of them, and that is why it's so popular.
If you're doing/teaching scientific computing with Python, it's widely used, if not "the" standard. Anaconda will almost certainly be available in any current scientific computing environment.
Since when? I was under the impression it's a data science focused alternative to the standard tools(pip, venv module, eventually pipenv).