Implying they're a risk is not the same as showing that bacterial counts from ties are causing patient disease. To quote the article itself:
"Because this topic lacks the level of evidence required for a more formal guideline using the GRADE system, no grading of the evidence level is provided for individual recommendations."
"HCP apparel can hypothetically serve as a vector for pathogen cross-transmission in healthcare settings; however, no clinical data yet exist to define the impact of HCP apparel on transmission. The benefit of institutional laundering of HCP scrubs versus home laundering for non-OR use remains unproven."
Again, if you swabbed everything in the patient's room, you'll find bacteria everywhere, including MRSA.