As for the idea that these laws were "previously unenforced," that's misleading. Falsifying business records has been prosecuted as a felony in New York many times before, including against other executives. What makes this case unique is the high-profile defendant, not some unprecedented application of the law.
And the claim that the prosecutor herself engaged in inflating asset prices is a distortion. Letitia James, as AG, pursued civil fraud claims against Trump for devaluing his assets for tax purposes while inflating them for loan applications—something Trump himself admitted to in depositions. That’s not the same as falsifying business records.
So no, this isn't some brand-new legal strategy being used against Trump; it's just a matter of finally holding a powerful person accountable under laws that have existed and been applied before.