I read some of the article's comments and many asked virtually the same question as you. One had a reply citing the Al-Iman mosque in Bronx, NY that allowed Jewish services.
I did a web check and found a Bronx Chabad Orthodox Jewish congregation that was allowed the use of a Muslim congregation's storefront mosque in the Bronx. Truly a brave and tolerant act on the part of that small and isolated Muslim congregation.
But, can a claim to ecumentalism for a religion of billions be supported by only a minuscule congregation in a rundown storefront in a deserted ghetto backwater?
Compare this to the Washington National Cathedral in a Christian nation's capital, where worshipers at each Sunday Service number close to two thousand (and the highest for any Episcopal church in the US) with additional hundreds of thousands of other visitors each year. [See wikipedia.]
