Not necessarily true. Owning a 2nd home doesn't automatically make that your tax home, regardless of how long you own it, or live in it. However, owning a 2nd home, the mortgage interest and property taxes are deductible on the federal return up to a limit. That has nothing to do with your tax home or how long you owned it, or how long you lived in it.
For all personal use real estate property if the combined mortgage outstanding balance on Jan 1 of the tax year is $750K or less, then all mortgage interest paid on all personal use real estate is deductible up to a maximum of $10K of the total mortgage interest paid.
As for property taxes, that's not clear yet. But read section 2 of the IRS notice at https://www.irs.gov/pub/irs-drop/n-18-54.pdf for the latest information I am able to find on this.