Character Designer Nicholas Kole has peeled the curtain back ever so slightly to let us all know that a Crash Bandicoot 5 was at some point in the works and (at least that version) no longer is.
Taking to X to talk about a couple cancelled projects, Nicholas mentions that while the original project he's talking about isn't Spyro or Crash but that a Crash 5 was cancelled.
"Some day folks will hear about the Crash 5 that never came to be it's going to break hearts".

No other details are given so it's unlikely we will learn much more anytime soon. Whether this was simply a game in it's concept stage that never advanced past that or if it was a game in active development and got shelved only time will tell. We also don't have a timeline on this Crash 5.
Rumours have been rampant that a Crash 5 is in development for years now. Whether it was this project and it has now been cancelled or if it's an entirely new game has yet to be seen (if it even exists). The developers of the franchise Toys For Bob recently left the Activision publishing umbrella to become independent but later signed a deal to have their next game published under Xbox publishing.
While there's still some hope for a new Crash Bandicoot this news will certainly sting for awhile.