In the context of the Linux kernel, tainted basically means it is not supported by the community/upstream. And as soon as you load some external, third-party, proprietary module, such as Nvidia official driver, Linux community can’t basically guarantee or support things as they are outside of their realm.
The only way would be I guess to either use Nouveau driver or that Nvidia decides to open-source and upstream their proprietary drivers to the Linux kernel.
So in that sense a question is a bit misguided.
Would you mind sharing the reasoning on why removing this message would be important to you?