This bug appears to have been reported against 'rawhide' during the Fedora 33 development cycle.
Changing version to 33.

I'm going to ramble on here a bit, because I figure that someone else may eventually run into this issue (or a similar one). I'm going to make texlive-latex depend on texlive-cm-super.

First, your suggestion of adding the cm-super dependency to collection-latex is probably something upstream should consider, but since they pretty clearly and explicitly set the requires there, it would not be appropriate for Fedora to diverge. The texlive collection sources are pretty simple, they just contain a .tlpobj which lists all the dependencies for the collection. collection-latex.tlpobj does not contain cm-super. It doesn't contain cm either, but that is pulled in by the dependency on collection-basic, which depends on cm (but only cm). cm doesn't depend on cm-super either.
cm-super is a Requires for collection-fontsrecommended, which in turn is required by collection-latexrecommended (which requires collection-latex).

I think your best bet would be to adjust your Requires to texlive-collection-latexrecommended to future-proof yourself.

However, there is a legitimate regression here. cm-super is clearly required now where it was not before. I wanted to know why this worked before and doesn't now, because I didn't remove/change cm-super anywhere. I dug into this at length and it looks like the tex function "itemize" is what triggers this. "enumerate", which seems to have almost identical logic, does not.

Here's my test code:

*****

\documentclass[12pt]{article}

\begin{document}
\begin{itemize}
%\begin{enumerate}

\item Hello World.

%\end{enumerate}
\end{itemize}
\end{document}


*****

The key difference between itemize and enumerate is this: itemize uses a "bullet" in front of items, where enumerate makes a numbered list. On a hunch, I overrode the default "bullet" like this:

\item[--] Hello World.

And sure enough, cm-super isn't needed anymore.

The "bullet" is defined by \DeclareTextSymbol{\textbullet}{TS1}{136}, and this lead me to changes in textcomp (part of texlive-latex). It used to handle \textbullet differently, and now it expects a TS1 font to provide it. The default TS1 font is... cm-super.

Since having "itemize" work properly seems like something that most people would expect to have happen (even with just collection-latex), I'm adding an explicit Requires: texlive-cm-super to texlive-latex in Fedora 33+.

Whoa, you dug deep. Thanks!

Requires added in texlive-base-20200327-15.fc33 (and .fc34).