Yeah, I think OSR might be more appropriate to "inspired by TSR-era D&D".
I wrote "OSR" on the cover of my latest book. It is mostly for B/X, LL, OSE, etc. Would it be fair to put OSR on the cover if it war intended for Traveller or WFRP? I don't think so.
Then we wave self-reporting. Look at the OSR games at DTRPG.
The most popular right now are: Dwarrowdeep, Sword & Caravan, Worlds Without Number, The Halls of Arden Vul, DCC...
(and a Traveller book is the most popular book today!)
Here is DTRPGs categories under OSR:
Old-School Revival (OSR)
Castles & Crusades
Dungeon Crawl Classics
Labyrinth Lord
Mork Borg
Old-School Essentials
OSRIC
Swords & Wizardry
Other OSR Games
Then there stuff like Warlock! (a FF clone)... "Other OSR Games". That's a catch-all for all non-D&D, inspired by early games. I'm not sure this is useful as a tag. I think I've got to admit that games like this are OSR-inspired; they wouldn't exist without the OSR. But these are less than 5% of top OSR titles.
I'm not sure what to make of these titles, TBH. My first book is "Other OSR Games" because it isn't OSRIC, LL, etc., but it has 10 levels, six stats, five classes and so on. What does it have to do with Warlock or Zweihander? Maybe some aesthetic choices, or the fact that they are inspired by earlier games (but aren't they all?)
You might object to using DTRPG as a mausre but I think it makes the OSR commercially viable at this moment, since there are not many other options (at least for me).