I'm not so sure how much this movie can be appreciated without a connection to the source but I also don't feel like that connection is in place of a movie.Where basically the draw to the project is more about the throw-backs, easter eggs, etc more than the actual film. The 80s retro stuff got so huge with Stranger Things, etc that people were focusing more on the set or nods... than actually creating good content.
Like most things... there is such a thing as 'too much of a good thing'. I think SMB has a good balance... the inclusions are not over the top and it doesn't feel forced all the time. You can still appreciate the characters/etc without a connection to their source.
There is a lot they just don't explain. Some of that is because nobody familiar with the source needs an explanation and some of it is because there is stuff they've never explained in the source (that I'm aware of) and that's all stuff none of us really want a complicated back-story to make sense of.
We don't know how blocks float or how rainbow road is a thing or how Coopas become undead but we also don't really need or want to. We accepted all of this a long, long time ago.
When a certain turtle yells a certain color, we all know what it means - no explanation and no confusion about what just happened, there.
As a person with no point of reference, some of this would, I think, be confusing or make certain aspects of the movie seem a little too convenient or rushed.
But that's what makes this movie unique. It's hard to think of another franchise/IP where they could gloss over so much of it and have such a large audience be perfectly okay with that.