Does anyone know what happens if you buy a bundle that includes a game that you got free via PS+? Does that game stop being a PS+ free game and turn into a regularly purchased game?
Answering my own question for anyone who cares.
Decided to be a guinea pig and just try it, so I bought the Sound Shapes Ultimate Bundle, which includes the game and DLC. I had gotten the game free at some point back in 2015 via PS+. Before the purchase, the Information Screen on my PS4 gave a "Valid to" date (indicating it was a free PS+ title) and PSDLE also confirmed it.
After the purchase, the game's Information Screen still said the same thing, so I deleted the game and re-downloaded it. Now the game no longer shows a "Valid to" date, and PSDLE also shows it listed as not a free PS+ title. Success!