For a non-resident alien spouse who met all the criteria for being an exemption on my 2017 MFS tax return, can that NRA spouse now be a dependent on my 2018 return?

The general TT advice says spouses can never be dependents. But in a 2018 updated TT article on "Claiming a Non-Citizen Spouse," it says they likely can be claimed as dependent, assuming they're NRA, have no U.S. income and can't be a dependent on anyone else's return. Which is it?