Some owners are reporting that Polaris hasn't addressed ALL the potential leaks so later units are NOT necessarily OK. Potential leak spots:
Top of access door -- intake hood sucks dust thru gap. Picture "french smoking" LOL
Intake box floor gasket -- Big gaps here allow dust to enter & get sucked into filter box.
Filter box duct -- some have small gaps where it screws to the filter box.
Filter Box Lid -- Ungreased or poor O-ring seal or broken clamps allow dirt into filter box.
Filter box clamp -- Some units left the factory with the box not clamped to the throttle body.

Filter collar -- loose or ungreased collar can let dust leak past & into throttle body.
The Polaris TSB (it's NOT a recall--you won't get a notice) only addresses 1 & 2...plus a little foam disc they put in the lid pushes on the fiilter to help keep it from wiggling loose but this may make the lid fit even worse.
I have a July unit and never had any problems. I gasketed & clamped the access door & caulked the intake box ducts as extra insurance. If I had a later unit I'd still keep a close watch on it until I knew for sure I had a good one.