The "latest release" marker in Github still points to 0.8.3 -- the box should be visible here:
https://github.com/flot/flot/releases?after=v2.1.5
I agree things are a bit confusing. Was this a fork ("engineering-flot") at one point that was re-integrated back into mainline? Trying to trace back the history and possibly poke Fedora for an update to the nodejs-flot package, which remains at that release, however there have obviously been lots of changes since then. If the "latest release" does get updated, it might be helpful for a small FAQ update with any clear gotchas for that jump.
[root@f30 /]# rpm -qa nodejs-flot
nodejs-flot-0.8.3-9.fc30.noarch
[root@f30 nodejs-flot]# ls -l
total 44
-rw-r--r--. 1 root root 40290 Apr 21 2014 NEWS.md
-rw-r--r--. 1 root root 3782 Apr 21 2014 README.md
Also, the NEWS link on the main page may need to be updated to CHANGELOG, given the note in the Changelog itself.
-jc