Small switching regulator EMI
While I don't think for this product we need to technically be
  concerned about EMI, I'm curious if a little bitty switching regulator
  like this generates all that much noise?


Yes, it does, or it can. And if this commercial product is going to be sold, it will most likely need to conform to IEC 61010 and pass the FCC unintentional radiators testing at an ETL. (all of which costs 5k to 10k $ depending on the ETL/Testing). 

It doesn't matter what kind of filtering you have, as long as it passes the tests. 

Switching regulators can radiate noise and conduct noise into AC mains with an improper design, a good thing to do is find a place or equipment to do precompliance testing. (the less time at an ETL, the less you get billed). Proper EMI design is a must. 

For these reasons, if I am designing a commercial product in low-ish quantities, I do a cost analysis and usually I buy and off the shelf power supply to decrease testing costs.