I read that the IRS actually said that. However, when I lived in CA I sometimes timed my property tax payments to adjust my deductions and never was questioned about it. Maybe because mine weren’t extraordinary high.
One person deciding which year to take a deduction in won't attract attention. A "stampede" of people trying to sneak one last extra year of deduction will get some notice. I fear that Congress will update this law to retroactively prevent it.
I don’t know their rationale but I think it may have something to do with whether the state’s real estate tax rolls are open for payment. IOW, they may take the stance you cannot pay ahead for a tax that is not due.
With the standard deduction set at 24K, one would have to have a lot of real estate tax, contributions, medical, and income taxes to be worried about this and also have to consider the tax bracket rates will be lower too.
Since auditing such a thing would be a nightmare, they may only take on the most egregious of the deduction scams. The selection program would have to examine whether itemized deductions jumped between TY 16 and TY17. Frankly were I making the call, I would not worry about it and just leave it to be picked up in the random audits done each year.