I would go even further and state that TIOBE is deprived of any meaningful value. It's basically a index that tracks web noise. I mean with TIOBE, C++'s ranking goes up if someone writes a blog post with a joke that goes "A C++ developer walks into a bar...".
I wouldn't be surprised if this post in HN is contributing to the bump.
TIOBE is what you get from garbage-in.
> I wouldn't put much stock in this and I like C++.
I would bet that C++20 led some bloggers to post random stuff with C++ in it.
But C++ usage really is growing faster than ever, judging by the number of C++ conferences that had been scheduled in 2020, and the monotonically increasing number of attendees at the far-flung, tri-ennial ISO C++ Standard conferences.
But TIOBE is not a reliable measure; when it's right, it is as accidental as the stopped clock that is right twice a day.
But you're also right that some of the larger trends are suspect as well. The big dip in C and Java in 2016-2017 could just as easily be due (at least in part) to a change in Google's search algorithm. The index doesn't solely rely on Google, but it certainly makes up a large part of the index [1].
There's no perfect metric for any of this, but making announcements about 1-month changes to a noisy estimate is not particularly convincing.
[0] https://www.tiobe.com/tiobe-index/cplusplus/
[1] https://www.tiobe.com/tiobe-index/programming-languages-defi...