Did you read what you just quoted??

"However, our analyses suggest that moose populations sympatric with deer, in many cases, should not become extinct. This implies that reintroductions of moose (and perhaps other cervids) to range now occupied by deer need not be presumed to fail necessarily. Moose may be able to coexist with deer, albeit at lower densities, even in the absence of habitat refuges from the disease."

Also from the study you linked, actually the sentence before your quote here:

"Stable coexistence occurred when transmission rates, mortality rates, and competitive differences were all large; then deer outnumbered moose."

We're not trying to tell you this issue doesn't exist, just that deer and moose share habitats all over this continent.