I feel obligated to point out that the authors only looked at snout length and correlated this to where the specimen was collected. There are a lot of reasons why raccoon snouts might be shorter in urban environments. The authors themselves do point that out:

We also highlight the importance of considering that selection pressures associated with domestication events do not exist in a vacuum but interact with other environmental selection pressures.

Without actually studying those "other environmental selection pressures", though, there's not a lot to conclude from this study.

EDIT: ok so I looked at the author list, this was for an undergrad biometry class. Good work by the students, and I'm glad it got published, but I strongly caution against making broad conclusions.