This is exactly what I was saying a couple weeks ago about how it's not like our offense is going to be completely unrecognizable, there are only so many routes WR's can run and so many blocking schemes you can utilize in the running game.
The real difference, and what the best offensive minds do, is adding slight wrinkles in to plays that you always see to throw defenses off balance, they make runs look like passes and passes look like runs, particularly play-action, and they have the awareness to know when to attack and exploit certain matchups with their play design, and they never stop looking for little ways to iterate and change things up slightly to stay ahead of defenses.
The 49ers weren't doing anything completely groundbreaking last year, they did some interesting stuff by mixing Gap and Zone principles in their run game but none of it was mind-blowing and you can actually see some of it in college here and there. They just did a great job of mixing up their play calls, throwing defenses off balance with slight misdirection, and specifically in designing play-action that looked exactly like it was going to be a run and then leaking guys out into wide open areas.
One of my biggest complaints over the years with the offensive design is that we'd often seem to be running plays in a vacuum, almost like, "ok let's try this, now let's do that, ok this one's good, let's give it a go, we haven't ran in a few plays let's just run our standard Inside Zone Right".
There was very little integration or cohesion as far as building concepts off each other and iterating to add new wrinkles and very little game planning specifically to exploit certain matchups, at least relative to the rest of the league. It just seemed like a mindset of "we have our plays and we're going to run them" with no real consideration of the matchups or teams being able to key in on what we do.
Thankfully I think that mindset is long gone now.