Every game has cuts. Delays prevent them. Watchdogs was an extreme case where, the developer made grandiose promises WAY too early in development. And showed off an incredible looking game exceedingly early...than went dark when they realized they couldn't pull it off. Their delay was obviously a scramble to rework the game entirely.
Witcher 3 has trickled information, has looked better each time, and hasn't shown us much even to this point. Anything the devs have talked about confidently or shown us is extremely unlikely to get cut. It is an ambitious game, they realize needs more than a few months of polish before it is ready (a fall release would mean the game goes gold and preps for shipping in 3-4 months). We've also been told the game is now playable from start to finish. But yes, in the process of extra testing they may realize a certain quest doesn't add anything to the game, and cut it to prevent it from taking unnecessary resources...but that isn't necessarily bad cut content...that would be good in my opinion. They may also notice a certain sign mechanic just ends up not functioning as intended, or that the Igni firewall is simply better than any other option, and current mechanics may be changed during the extra time.
Delay's aren't inherently good or bad. They depend entirely on the efficacy of the development team and their commitment to their product. Everything CDPR has done, said, and shown us to date has done nothing but to ensure my confidence that they will do what is best for their end product, and that any changes made will be because they legitimately believe it increases the quality of the game.
CDPR has done nothing but improved since they first released Witcher 1, every change they have made in Enhanced Editions etc has always objectively improved their product, they've always held fan feedback in high regard. They are in full control of their own game as well, which is important. They publish and develop it. They're driven internally, not pressured externally. I don't see a reason to worry.